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Alfresco Process Automation

BPMN

BPMN elements are used to model processes and include other models created within a project into a process definition.

Start events

A process must always contain at least one start event as they define how a process begins.

The types of start event are:

Start event

Start events are where the trigger is unspecified for starting a process. The trigger can be using a form, manually through the Digital Workspace, using the REST API or from a trigger.

  • Properties
  • Basic properties

    The basic properties for a start event are:

    Property Description
    ID Required. The unique identifier for the start event. This is system generated and cannot be altered, for example StartEvent_1w29b3h.
    Name Optional. The name of the start event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the start event does.

    Form name

    An optional form can be used to begin a process. The form must exist within the same project as the process definition to be selected. Select a form from the dropdown, else create a new form using the + symbol.

    Once a form has been selected, it can be edited using the Open Form symbol.

    Mapping type

    The mapping type sets how data is passed between the start event and the process. There are five options for how to send this data. The default value is Send no variables.

  • Appearance
  • Start events are displayed as a single thin circle without an icon inside.

  • XML
  • An example of the XML of a start event without a form defined is:

    <bpmn2:startEvent id="StartProcess_1" name="FormStart_4">
    	<bpmn2:outgoing>SequenceFlow_1</bpmn2:outgoing>
    </bpmn2:startEvent>
    

    An example of the XML of a start event with a form defined is:

    <bpmn2:startEvent id="StartProcess_1" name="FormStart_4" activiti:formKey="form-4ccd023b-d607-4cab-8623-da4c87dd9611">
    	<bpmn2:outgoing>SequenceFlow_1</bpmn2:outgoing>
    </bpmn2:startEvent>
    

    Note: The activiti:formKey is the id of the form used to start the process.

Error start event

Error start events can only be used in event sub-processes. They begin an event sub-processes when a named error is received.

  • Properties
  • Basic properties

    The basic properties for an error start event are:

    Property Description
    ID Required. The unique identifier for the error start event. This is system generated and cannot be altered, for example StartEvent_1w29b3h.
    Name Optional. The name of the error start event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the error start event does.

    Form name

    An optional form can be used to begin a process. The form must exist within the same project as the process definition to be selected. Select a form from the dropdown, else create a new form using the + symbol.

    Once a form has been selected, it can be edited using the Open Form symbol.

    Mapping type

    The mapping type sets how data is passed between the error start event and the process. There are five options for how to send this data. The default value is Send no variables.

    Error

    An error needs to be defined for the error start event to catch. A previously created Error can be selected from the dropdown in its properties, or a new one created using the + symbol. An Error name and Error code can then be set.

  • Error
  • Error events are used to model an exception in a business process. Errors are thrown by error end events and caught by error start events and error boundary events.

    The errorRef property in the errorEventDefinition of an error event element will match against the id of an error when viewing the XML Editor.

    Error events are displayed as a lightning bolt icon inside different shapes that differentiate between the event types. A solid lightning bolt represents a throwing event, whilst a hollow lightning bolt represents a catching event.

    To create a new error use the + symbol against an error event such as a start error event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Errors button will be visible in the right-hand properties panel.

  • Appearance
  • Error start events are displayed as a single thin circle with a hollow lightning bolt icon inside.

  • XML
  • An example of the XML of an error start event is:

    <bpmn2:startEvent id="StartEvent3">
    	<bpmn2:errorEventDefinition errorRef="Error_0vbkbeb" />
    </bpmn2:startEvent>
    

    An example of the XML of an error is:

    <bpmn2:error id="Error_0vbkbeb" name="payment-failed-error" errorCode="404" />
    

Message start event

Message start events begin a process instance when a named message is received.

  • Properties
  • Basic properties

    The basic properties for a message start event are:

    Property Description
    ID Required. The unique identifier for the message start event. This is system generated and cannot be altered, for example StartEvent_1w29b3h.
    Name Optional. The name of the message start event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the message start event does.

    Form name

    An optional form can be used to begin a process. The form must exist within the same project as the process definition to be selected. Select a form from the dropdown, else create a new form using the + symbol.

    Once a form has been selected, it can be edited using the Open Form symbol.

    Mapping type

    The mapping type sets how data is passed between the message start event and the process. There are five options for how to send this data. The default value is Send no variables.

    Message

    A message needs to be defined for the message start event to catch when it is thrown. A previously created Message can be selected from the dropdown in its properties, or a new one created using the + symbol. A Message name and payload can then be set.

  • Message
  • Message

    Messages have a name and contain a payload. They are sent by message throwing events and received by message catching events in a 1:1 relationship between throw events and catch events. Messages contain a payload known as a message payload and can be passed between scopes, for example between two different process definitions within the same diagram that are separated by different pools.

    The message id property of a message is matched against the messageRef property in the corresponding throw and catch message elements when viewing the XML Editor.

    To create a new message use the + symbol against a message event such as a message boundary event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Messages button will be visible in the right-hand properties panel.

    Message events are displayed as an envelope icon inside different shapes that differentiate between the event types. A solid envelope represents a throwing event, whilst a hollow envelope represents a catching event.

    Message payloads

    Message payloads contain a set of values that are sent from a throwing event and received by a catching event.

    Message payloads can only be created on a message throw event and contain one or more properties that have a name, type and value. The property types for payloads are:

    Type Description
    String A sequence of characters, for example #Mint-Ice-Cream-4!
    Integer A positive whole number, for example 642
    Boolean A value of either true or false
    Date A specific date in the format YYYY-MM-DD, for example 2020-04-22
    Variable A value passed from a process variable.

    The receiving message catch event is then used to map the received values in the payload to process variables in its own scope.

    Message payload mappings can be viewed in the Extensions Editor of a process diagram. Throwing events are mapped as inputs and catching events are mapped as outputs from an event.

    Correlation keys

    Message events can optionally contain a correlation key. If a correlation key is present then when a message is thrown it uses the activiti:correlationKey value and the messageRef of the throwing event to match against the same two properties in a catching event. If only one property is matched then the message will not be caught.

    Using a process variable for the correlation key in a throwing event and a static value for its corresponding catching event allows for the message to only be caught in specific circumstances.

    Note: Message start events cannot contain a correlation key unless they are used in a sub process.

    Message flows

    When messages are used between two different pools the sequence flow that connects them is a dotted line called a message flow. The message flow is part of the collaboration element in the XML created by introducing a pool. Message flows reference the throwing message event as the sourceRef and the catching message event as the targetRef.

  • Appearance
  • Message start events are displayed as a single thin circle with a hollow envelope icon inside.

  • XML
  • An example of the XML of a message start event is:

    <bpmn2:startEvent id="StartEvent2">
    	<bpmn2:outgoing>SequenceFlow_1</bpmn2:outgoing>
    	<bpmn2:messageEventDefinition messageRef="Message_15xakkk" />
    </bpmn2:startEvent>
    

    An example of the XML of a message is:

    <bpmn2:message id="Message_15xakkk" name="Message_15xakkk" />
    

    An example of the XML of a message payload is:

        "mappings": {
            "EndEvent_0ss2fp3": {
                "inputs": {
                    "name": {
                        "type": "variable",
                        "value": "username"
                    },
                    "order-number": {
                        "type": "value",
                        "value": 1459283
                    }
                }
            }
        },
    

    An example of the XML of a message with a correlation key is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_1hxecs2" activiti:correlationKey="${userId}" />
    

    In this example the message will only be caught if a catching event has a messageRef of Message_1hxecs2 and an activiti:correlationKey that matches the value of userId.

    An example of the XML of a message flow is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    	<bpmn2:messageFlow id="MessageFlow_0vh4zdb" sourceRef="Event_00acemq" targetRef="Event_13u5jtf" />
    </bpmn2:collaboration>
    

Signal start event

Signal start events begin a process instance using a caught, named signal.

  • Properties
  • Basic properties

    The basic properties for a signal start event are:

    Property Description
    ID Required. The unique identifier for the signal start event. This is system generated and cannot be altered, for example StartEvent_1w29b3h.
    Name Optional. The name of the signal start event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the signal start event does.

    Signal

    A signal needs to be defined for the signal start event to catch. A previously used Signal can be selected from the dropdown in its properties, or a new one created using the + symbol. A Signal name can then be set.

    Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

  • Signal
  • Signal events can be either catching or throwing. A throwing signal event will emit a signal when it is reached in a process instance that will be picked up by any catching signal event with a matching signal name. Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

    The id of a signal will match against the signalRef of a catching or throwing event.

    Signal events are displayed as a triangle icon inside different shapes that differentiate between the event types. A solid triangle represents a throwing event, whilst a hollow triangle represents a catching event.

  • Appearance
  • Signal start events are displayed as a single thin circle with a hollow triangle icon inside.

  • XML
  • An example of the XML of a signal start event is:

    <bpmn2:startEvent id="StartEvent1">
    	<bpmn2:outgoing>SequenceFlow_1</bpmn2:outgoing>
     	<bpmn2:signalEventDefinition signalRef="Signal_0hnsd2r" />
    </bpmn2:startEvent>
    

    An example of the XML of a signal with a global scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" />
    

    An example of the XML of a signal with a process instance scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" activiti:scope="processInstance" />
    

Timer start event

Timer start events begin a process at a specific time once or repeatedly at intervals.

  • Properties
  • Basic properties

    The basic properties for a timer start event are:

    Property Description
    ID Required. The unique identifier for the timer start event. This is system generated and cannot be altered, for example StartEvent_1w29b3h.
    Name Optional. The name of the timer start event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the timer start event does.

    Form name

    An optional form can be used to begin a process. The form must exist within the same project as the process definition to be selected. Select a form from the dropdown, else create a new form using the + symbol.

    Once a form has been selected, it can be edited using the Open Form symbol.

    Mapping type

    The mapping type sets how data is passed between the timer start event and the process. There are five options for how to send this data. The default value is Send no variables.

    Timer

    A choice of timer must be set for timer start events, based on a Cycle, Date or Duration.

  • Timer
  • Timer events are used to influence events at specific times, after a set amount of time has passed or at intervals. All timer events use the international standard ISO 8601 for specifying time formats.

    Note: All properties within timerEventDefinition can accept process variables as their values as long as they are in ISO 8601 or cron expression format.

    Timer events are displayed as a clock icon inside different shapes that differentiate between the event types.

    timeDate

    The timeDate property for timer events defines a specific date and time in ISO 8601 format for when the trigger will be fired and can include a specified time zone.

    The following is an example of the timerEventDefinition using a timeDate:

    • 2017-05-17 represents the 17th May 2017 in YYYY-MM-DD format
    • T12:42:23 represents the time of 12:42:23 in hh:mm:ss format
    • Z represents that the time format is in UTC (Coordinated Universal Time). The time can also contain UTC offsets such as +01 for an hour ahead of UTC. When an offset is defined the Z is not required, for example: T12:42:23+01

    timeDuration

    The timeDuration property for timer events defines how long a timer should wait in ISO 8601 format before the trigger is fired.

    The following are the letters used to refer to duration:

    Letter Description
    P Designates that the following letters and numbers represent a duration. Must always be present
    Y Represents a year and follows the number of years, for example P2Y is 2 years
    M Represents a month and follows the number of months when preceded by a P, for example P3Y4M is 2 years and 4 months
    W Represents a week and follows the number of weeks, for example P10W for 10 weeks
    D Represents a day and follows the number of days, for example P1Y1M1D for 1 year, 1 month and 1 day
    T Designates that the following letters represent a duration of hours to seconds. Must always be present to refer to hours, minutes and seconds
    H Represents an hour and follows the number of hours, for example P1DT0.5H for 1 day and half an hour
    M Represents a minute and follows the number of minutes when preceded by a T, for example PT1M for 1 minute
    S Represents a second and follows the number of seconds, for example P2Y3M4DT5H6M7S for 2 years, 3 months, 4 days, 5 hours, 6 minutes and 7 seconds

    timeCycle

    The timeCycle property for timer events defines intervals for the trigger to fire at. Intervals can be defined using the time intervals that adhere to the ISO 8601 standard or by using cron expressions.

    Time intervals

    Time intervals use the syntax R/ to set a number of repetitions, for example R5/ would repeat five times.

    Following the repetition, a duration can be set for when the repetition occurs, for example R5/PT10H would repeat every 10 hours, five times.

    Note The duration uses the same format as for timeDuration.

    An optional end date can also be set after the duration and separated by a /.

    Note: The end date uses the same format as for timeDate.

    Cron expression intervals

    Cron expressions can also be used to define repeating triggers for timer events.

  • Appearance
  • Timer start events are displayed as a single thin circle with a clock icon inside.

  • XML
  • An example of the XML of a timer start event is:

    <bpmn2:startEvent id="StartEvent3">
        <bpmn2:outgoing>SequenceFlow_1</bpmn2:outgoing>
        <timerEventDefinition>
            <timeCycle xsi:type="bpmn2:tFormalExpression">R10/2020-12-10T13:00/PT12H</timeCycle>
        </timerEventDefinition>
    </bpmn2:startEvent>
    

    Note: This will start the process 10 times, at 12 hour intervals starting on the 10th December 2020.

    An example of the XML for timeDate is:

    <bpmn2:timerEventDefinition> 
      <bpmn2:timeDate xsi:type="bpmn2:tFormalExpression">2017-05-17T12:42:23Z</bpmn2:timeDate>
    </bpmn2:timerEventDefinition>
    

    An example of the XML for timeDuration is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">P5D</bpmn2:timeDuration>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a duration of 5 days.

    An example of the XML for timeCycle using time interval syntax is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle xsi:type="bpmn2:tFormalExpression">R3/PT30M</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition> 
    

    Note: This represents three repetitions every 30 minutes.

    An example of the XML for timeCycle using a cron expression is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle>0 0/5 * * * ?</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a trigger firing every 5 minutes beginning at the top of the hour.

End events

End events indicate where the current process flow ends, therefore there can be no outgoing sequence flow from an end event. Different types of end event can have have actions other than just ending the process flow execution path.

The types of end event are:

End event

End events complete the process flow with no additional behavior.

  • Properties
  • Basic properties

    The basic properties for an end event are:

    Property Description
    ID Required. The unique identifier for the end event. This is system generated and cannot be altered, for example EndEvent_00ln22h.
    Name Optional. The name of the end event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the end event does.
  • Appearance
  • End events are displayed as a single thick circle without an icon inside.

  • XML
  • An example of the XML of an end event is:

    <bpmn2:endEvent id="EndEvent_1">
        <bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    </bpmn2:endEvent>
    

Error end event

Error end events throw an error when the process flow reaches them.

  • Properties
  • Basic properties

    The basic properties for an error end event are:

    Property Description
    ID Required. The unique identifier for the error end event. This is system generated and cannot be altered, for example EndEvent_00ln22h.
    Name Optional. The name of the error end event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the error end event does.

    Error

    An error needs to be defined for the error end event to throw. A previously created Error can be selected from the dropdown in its properties, or a new one created using the + symbol. An Error name and Error code can then be set.

  • Error
  • Error events are used to model an exception in a business process. Errors are thrown by error end events and caught by error start events and error boundary events.

    The errorRef property in the errorEventDefinition of an error event element will match against the id of an error when viewing the XML Editor.

    Error events are displayed as a lightning bolt icon inside different shapes that differentiate between the event types. A solid lightning bolt represents a throwing event, whilst a hollow lightning bolt represents a catching event.

    To create a new error use the + symbol against an error event such as a start error event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Errors button will be visible in the right-hand properties panel.

  • Appearance
  • Error end events are displayed as a single thick circle with a solid lightning bolt icon inside.

  • XML
  • An example of the XML of an error end event is:

    <bpmn2:endEvent id="EndEvent_1">
        <bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
        <bpmn2:errorEventDefinition errorRef="Error_3vbkafg" />
    </bpmn2:endEvent>
    

    An example of the XML of an error is:

    <bpmn2:error id="Error_3vbkafg" name="payment-failed-error" errorCode="404" />
    

Message end event

Message end events complete the process flow and send a message event.

  • Properties
  • Basic properties

    The basic properties for a message end event are:

    Property Description
    ID Required. The unique identifier for the message end event. This is system generated and cannot be altered, for example EndEvent_00ln22h.
    Name Optional. The name of the message end event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the message end event does.

    Message

    A message needs to be defined for the message end event to send. A previously created Message can be selected from the dropdown in its properties, or a new one created using the + symbol. A Message name and payload can then be set.

  • Message
  • Message

    Messages have a name and contain a payload. They are sent by message throwing events and received by message catching events in a 1:1 relationship between throw events and catch events. Messages contain a payload known as a message payload and can be passed between scopes, for example between two different process definitions within the same diagram that are separated by different pools.

    The message id property of a message is matched against the messageRef property in the corresponding throw and catch message elements when viewing the XML Editor.

    To create a new message use the + symbol against a message event such as a message boundary event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Messages button will be visible in the right-hand properties panel.

    Message events are displayed as an envelope icon inside different shapes that differentiate between the event types. A solid envelope represents a throwing event, whilst a hollow envelope represents a catching event.

    Message payloads

    Message payloads contain a set of values that are sent from a throwing event and received by a catching event.

    Message payloads can only be created on a message throw event and contain one or more properties that have a name, type and value. The property types for payloads are:

    Type Description
    String A sequence of characters, for example #Mint-Ice-Cream-4!
    Integer A positive whole number, for example 642
    Boolean A value of either true or false
    Date A specific date in the format YYYY-MM-DD, for example 2020-04-22
    Variable A value passed from a process variable.

    The receiving message catch event is then used to map the received values in the payload to process variables in its own scope.

    Message payload mappings can be viewed in the Extensions Editor of a process diagram. Throwing events are mapped as inputs and catching events are mapped as outputs from an event.

    Correlation keys

    Message events can optionally contain a correlation key. If a correlation key is present then when a message is thrown it uses the activiti:correlationKey value and the messageRef of the throwing event to match against the same two properties in a catching event. If only one property is matched then the message will not be caught.

    Using a process variable for the correlation key in a throwing event and a static value for its corresponding catching event allows for the message to only be caught in specific circumstances.

    Note: Message start events cannot contain a correlation key unless they are used in a sub process.

    Message flows

    When messages are used between two different pools the sequence flow that connects them is a dotted line called a message flow. The message flow is part of the collaboration element in the XML created by introducing a pool. Message flows reference the throwing message event as the sourceRef and the catching message event as the targetRef.

  • Appearance
  • Message end events are displayed as a single thick circle with a solid envelope icon inside.

  • XML
  • An example of the XML of a message end event is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_45sdihj" />
    </bpmn2:endEvent>
    

    An example of the XML of a message is:

    <bpmn2:message id="Message_15xakkk" name="Message_15xakkk" />
    

    An example of the XML of a message payload is:

        "mappings": {
            "EndEvent_0ss2fp3": {
                "inputs": {
                    "name": {
                        "type": "variable",
                        "value": "username"
                    },
                    "order-number": {
                        "type": "value",
                        "value": 1459283
                    }
                }
            }
        },
    

    An example of the XML of a message with a correlation key is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_1hxecs2" activiti:correlationKey="${userId}" />
    

    In this example the message will only be caught if a catching event has a messageRef of Message_1hxecs2 and an activiti:correlationKey that matches the value of userId.

    An example of the XML of a message flow is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    	<bpmn2:messageFlow id="MessageFlow_0vh4zdb" sourceRef="Event_00acemq" targetRef="Event_13u5jtf" />
    </bpmn2:collaboration>
    

Terminate end event

Terminate end events cause the current process scope to be immediately ended, including any parallel process flows. The scope is determined by the location of the terminate end event. If the terminate end event is in a sub-process or call activity, only the sub-process or call activity instance will be ended, not the parent or originating process instance. In the case of a multi-instance sub-process or call activity only a single instance will be ended.

  • Properties
  • Basic properties

    The basic properties for a terminate end event are:

    Property Description
    ID Required. The unique identifier for the terminate end event. This is system generated and cannot be altered, for example EndEvent_00ln22h.
    Name Optional. The name of the terminate end event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the terminate end event does.
  • Appearance
  • Terminate end events are displayed as a single thick circle with a solid circle inside.

  • XML
  • An example of the XML of a terminate end event is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    	<bpmn2:terminateEventDefinition id="TerminateEventDefinition_0j911ut"/>
    </bpmn2:endEvent>
    

Intermediate events

Intermediate events can be used at any point throughout a process. They always provide additional behavior such as throwing a signal or catching a timer.

The types of intermediate event are:

Message intermediate catch event

Message intermediate catching events cause the process flow to wait until the message named in the messageRef property is received before it proceeds.

  • Properties
  • Basic properties

    The basic properties for a message intermediate catch event are:

    Property Description
    ID Required. The unique identifier for the message intermediate catch event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the message intermediate catch event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the message intermediate catch event does.

    Message

    A message needs to be defined for the message intermediate catch event to catch. A previously created Message can be selected from the dropdown in its properties, or a new one created using the + symbol. A Message name and payload can then be set.

  • Message
  • Message

    Messages have a name and contain a payload. They are sent by message throwing events and received by message catching events in a 1:1 relationship between throw events and catch events. Messages contain a payload known as a message payload and can be passed between scopes, for example between two different process definitions within the same diagram that are separated by different pools.

    The message id property of a message is matched against the messageRef property in the corresponding throw and catch message elements when viewing the XML Editor.

    To create a new message use the + symbol against a message event such as a message boundary event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Messages button will be visible in the right-hand properties panel.

    Message events are displayed as an envelope icon inside different shapes that differentiate between the event types. A solid envelope represents a throwing event, whilst a hollow envelope represents a catching event.

    Message payloads

    Message payloads contain a set of values that are sent from a throwing event and received by a catching event.

    Message payloads can only be created on a message throw event and contain one or more properties that have a name, type and value. The property types for payloads are:

    Type Description
    String A sequence of characters, for example #Mint-Ice-Cream-4!
    Integer A positive whole number, for example 642
    Boolean A value of either true or false
    Date A specific date in the format YYYY-MM-DD, for example 2020-04-22
    Variable A value passed from a process variable.

    The receiving message catch event is then used to map the received values in the payload to process variables in its own scope.

    Message payload mappings can be viewed in the Extensions Editor of a process diagram. Throwing events are mapped as inputs and catching events are mapped as outputs from an event.

    Correlation keys

    Message events can optionally contain a correlation key. If a correlation key is present then when a message is thrown it uses the activiti:correlationKey value and the messageRef of the throwing event to match against the same two properties in a catching event. If only one property is matched then the message will not be caught.

    Using a process variable for the correlation key in a throwing event and a static value for its corresponding catching event allows for the message to only be caught in specific circumstances.

    Note: Message start events cannot contain a correlation key unless they are used in a sub process.

    Message flows

    When messages are used between two different pools the sequence flow that connects them is a dotted line called a message flow. The message flow is part of the collaboration element in the XML created by introducing a pool. Message flows reference the throwing message event as the sourceRef and the catching message event as the targetRef.

  • Appearance
  • Message intermediate catching events are displayed as two thin concentric circles with a hollow envelope icon inside.

  • XML
  • An example of the XML of a message intermediate catch events is:

    <bpmn2:intermediateCatchEvent id="IntermediateCatchEvent2">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_6</bpmn2:outgoing>
        <bpmn2:messageEventDefinition messageRef="Message_6" />
    </bpmn2:intermediateCatchEvent>
    

    An example of the XML of a message is:

    <bpmn2:message id="Message_15xakkk" name="Message_15xakkk" />
    

    An example of the XML of a message payload is:

        "mappings": {
            "EndEvent_0ss2fp3": {
                "inputs": {
                    "name": {
                        "type": "variable",
                        "value": "username"
                    },
                    "order-number": {
                        "type": "value",
                        "value": 1459283
                    }
                }
            }
        },
    

    An example of the XML of a message with a correlation key is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_1hxecs2" activiti:correlationKey="${userId}" />
    

    In this example the message will only be caught if a catching event has a messageRef of Message_1hxecs2 and an activiti:correlationKey that matches the value of userId.

    An example of the XML of a message flow is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    	<bpmn2:messageFlow id="MessageFlow_0vh4zdb" sourceRef="Event_00acemq" targetRef="Event_13u5jtf" />
    </bpmn2:collaboration>
    

Message intermediate throw event

Message intermediate throw events send the message event named in the messageRef property when the process flow reaches them.

  • Properties
  • Basic properties

    The basic properties for a message intermediate throw event are:

    Property Description
    ID Required. The unique identifier for the message intermediate throw event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the message intermediate throw event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the message intermediate throw event does.

    Message

    A message needs to be defined for the message intermediate throw event to catch. A previously created Message can be selected from the dropdown in its properties, or a new one created using the + symbol. A Message name and payload can then be set.

  • Message
  • Message

    Messages have a name and contain a payload. They are sent by message throwing events and received by message catching events in a 1:1 relationship between throw events and catch events. Messages contain a payload known as a message payload and can be passed between scopes, for example between two different process definitions within the same diagram that are separated by different pools.

    The message id property of a message is matched against the messageRef property in the corresponding throw and catch message elements when viewing the XML Editor.

    To create a new message use the + symbol against a message event such as a message boundary event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Messages button will be visible in the right-hand properties panel.

    Message events are displayed as an envelope icon inside different shapes that differentiate between the event types. A solid envelope represents a throwing event, whilst a hollow envelope represents a catching event.

    Message payloads

    Message payloads contain a set of values that are sent from a throwing event and received by a catching event.

    Message payloads can only be created on a message throw event and contain one or more properties that have a name, type and value. The property types for payloads are:

    Type Description
    String A sequence of characters, for example #Mint-Ice-Cream-4!
    Integer A positive whole number, for example 642
    Boolean A value of either true or false
    Date A specific date in the format YYYY-MM-DD, for example 2020-04-22
    Variable A value passed from a process variable.

    The receiving message catch event is then used to map the received values in the payload to process variables in its own scope.

    Message payload mappings can be viewed in the Extensions Editor of a process diagram. Throwing events are mapped as inputs and catching events are mapped as outputs from an event.

    Correlation keys

    Message events can optionally contain a correlation key. If a correlation key is present then when a message is thrown it uses the activiti:correlationKey value and the messageRef of the throwing event to match against the same two properties in a catching event. If only one property is matched then the message will not be caught.

    Using a process variable for the correlation key in a throwing event and a static value for its corresponding catching event allows for the message to only be caught in specific circumstances.

    Note: Message start events cannot contain a correlation key unless they are used in a sub process.

    Message flows

    When messages are used between two different pools the sequence flow that connects them is a dotted line called a message flow. The message flow is part of the collaboration element in the XML created by introducing a pool. Message flows reference the throwing message event as the sourceRef and the catching message event as the targetRef.

  • Appearance
  • Message intermediate throwing events are displayed as two thin concentric circles with a solid envelope icon inside.

  • XML
  • An example of the XML of a message intermediate throw events is:

    <bpmn2:intermediateThrowEvent id="IntermediateThrowEvent1">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_6</bpmn2:outgoing>
        <bpmn2:messageEventDefinition messageRef="Message_6" />
    </bpmn2:intermediateThrowEvent>
    

    An example of the XML of a message is:

    <bpmn2:message id="Message_15xakkk" name="Message_15xakkk" />
    

    An example of the XML of a message payload is:

        "mappings": {
            "EndEvent_0ss2fp3": {
                "inputs": {
                    "name": {
                        "type": "variable",
                        "value": "username"
                    },
                    "order-number": {
                        "type": "value",
                        "value": 1459283
                    }
                }
            }
        },
    

    An example of the XML of a message with a correlation key is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_1hxecs2" activiti:correlationKey="${userId}" />
    

    In this example the message will only be caught if a catching event has a messageRef of Message_1hxecs2 and an activiti:correlationKey that matches the value of userId.

    An example of the XML of a message flow is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    	<bpmn2:messageFlow id="MessageFlow_0vh4zdb" sourceRef="Event_00acemq" targetRef="Event_13u5jtf" />
    </bpmn2:collaboration>
    

Signal intermediate catch event

Signal intermediate catching events cause the process flow to wait until the signal named in the signalRef property is received before it proceeds.

  • Properties
  • Basic properties

    The basic properties for a signal intermediate catch event are:

    Property Description
    ID Required. The unique identifier for the signal intermediate catch event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the signal intermediate catch event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the signal intermediate catch event does.

    Signal

    A signal needs to be defined for the signal intermediate catch event to catch. A previously used Signal can be selected from the dropdown in its properties, or a new one created using the + symbol. A Signal name can then be set.

    Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

  • Signal
  • Signal events can be either catching or throwing. A throwing signal event will emit a signal when it is reached in a process instance that will be picked up by any catching signal event with a matching signal name. Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

    The id of a signal will match against the signalRef of a catching or throwing event.

    Signal events are displayed as a triangle icon inside different shapes that differentiate between the event types. A solid triangle represents a throwing event, whilst a hollow triangle represents a catching event.

  • Appearance
  • Signal intermediate catching events are displayed as two thin concentric circles with a hollow triangle icon inside.

  • XML
  • An example of the XML of a signal intermediate catch events is:

    <bpmn2:intermediateCatchEvent id="IntermediateCatchEvent2">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_6</bpmn2:outgoing>
        <bpmn2:signalEventDefinition signalRef="Signal_0hnsd2r" />
    </bpmn2:intermediateCatchEvent>
    

    An example of the XML of a signal with a global scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" />
    

    An example of the XML of a signal with a process instance scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" activiti:scope="processInstance" />
    

Signal intermediate throw event

Signal intermediate throw events are events that emit a signal when they are reached in the process flow. The signal that is emitted is then caught by any catching signal events with a name matching the signal that was thrown.

  • Properties
  • Basic properties

    The basic properties for a signal intermediate throw event are:

    Property Description
    ID Required. The unique identifier for the signal intermediate throw event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the signal intermediate throw event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the signal intermediate throw event does.

    Signal

    A signal needs to be defined for the signal intermediate throw event to emit when it is reached. A previously used Signal can be selected from the dropdown in its properties, or a new one created using the + symbol. A Signal name can then be set.

    Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

  • Signal
  • Signal events can be either catching or throwing. A throwing signal event will emit a signal when it is reached in a process instance that will be picked up by any catching signal event with a matching signal name. Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

    The id of a signal will match against the signalRef of a catching or throwing event.

    Signal events are displayed as a triangle icon inside different shapes that differentiate between the event types. A solid triangle represents a throwing event, whilst a hollow triangle represents a catching event.

  • Appearance
  • Signal intermediate throw events are displayed as two thin concentric circles with a solid triangle icon inside.

  • XML
  • An example of the XML of a signal intermediate catch events is:

    <bpmn2:intermediateThrowEvent id="IntermediateThrowEvent1">
    	<bpmn2:incoming>SequenceFlow_3</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_4</bpmn2:outgoing>
       <bpmn2:signalEventDefinition signalRef="Signal_1jiw9tp" />
    </bpmn2:intermediateThrowEvent>
    

    An example of the XML of a signal with a global scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" />
    

    An example of the XML of a signal with a process instance scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" activiti:scope="processInstance" />
    

Timer intermediate catch event

Timer intermediate catching events cause the process flow to wait until a specific time or interval is reached. The time to wait is defined in the timerEventDefinition property.

  • Properties
  • Basic properties

    The basic properties for a timer intermediate catch event are:

    Property Description
    ID Required. The unique identifier for the timer intermediate catch event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the timer intermediate catch event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the timer intermediate catch event does.

    Timer

    A choice of timer must be set for timer start events, based on a Cycle, Date or Duration.

  • Timer
  • Timer events are used to influence events at specific times, after a set amount of time has passed or at intervals. All timer events use the international standard ISO 8601 for specifying time formats.

    Note: All properties within timerEventDefinition can accept process variables as their values as long as they are in ISO 8601 or cron expression format.

    Timer events are displayed as a clock icon inside different shapes that differentiate between the event types.

    timeDate

    The timeDate property for timer events defines a specific date and time in ISO 8601 format for when the trigger will be fired and can include a specified time zone.

    The following is an example of the timerEventDefinition using a timeDate:

    • 2017-05-17 represents the 17th May 2017 in YYYY-MM-DD format
    • T12:42:23 represents the time of 12:42:23 in hh:mm:ss format
    • Z represents that the time format is in UTC (Coordinated Universal Time). The time can also contain UTC offsets such as +01 for an hour ahead of UTC. When an offset is defined the Z is not required, for example: T12:42:23+01

    timeDuration

    The timeDuration property for timer events defines how long a timer should wait in ISO 8601 format before the trigger is fired.

    The following are the letters used to refer to duration:

    Letter Description
    P Designates that the following letters and numbers represent a duration. Must always be present
    Y Represents a year and follows the number of years, for example P2Y is 2 years
    M Represents a month and follows the number of months when preceded by a P, for example P3Y4M is 2 years and 4 months
    W Represents a week and follows the number of weeks, for example P10W for 10 weeks
    D Represents a day and follows the number of days, for example P1Y1M1D for 1 year, 1 month and 1 day
    T Designates that the following letters represent a duration of hours to seconds. Must always be present to refer to hours, minutes and seconds
    H Represents an hour and follows the number of hours, for example P1DT0.5H for 1 day and half an hour
    M Represents a minute and follows the number of minutes when preceded by a T, for example PT1M for 1 minute
    S Represents a second and follows the number of seconds, for example P2Y3M4DT5H6M7S for 2 years, 3 months, 4 days, 5 hours, 6 minutes and 7 seconds

    timeCycle

    The timeCycle property for timer events defines intervals for the trigger to fire at. Intervals can be defined using the time intervals that adhere to the ISO 8601 standard or by using cron expressions.

    Time intervals

    Time intervals use the syntax R/ to set a number of repetitions, for example R5/ would repeat five times.

    Following the repetition, a duration can be set for when the repetition occurs, for example R5/PT10H would repeat every 10 hours, five times.

    Note The duration uses the same format as for timeDuration.

    An optional end date can also be set after the duration and separated by a /.

    Note: The end date uses the same format as for timeDate.

    Cron expression intervals

    Cron expressions can also be used to define repeating triggers for timer events.

  • Appearance
  • Timer intermediate catch events are displayed as two thin concentric circles with a clock icon inside.

  • XML
  • An example of the XML of a signal intermediate catch events is:

    <bpmn2:intermediateCatchEvent id="IntermediateCatchEvent5">
    	<bpmn2:incoming>SequenceFlow_3</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_4</bpmn2:outgoing>
    	<bpmn2:timerEventDefinition>
      		<bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">P5D</bpmn2:timeDuration>
    	</bpmn2:timerEventDefinition>
    </bpmn2:intermediateCatchEvent>
    

    Note: This will wait five days before continuing the process.

    An example of the XML for timeDate is:

    <bpmn2:timerEventDefinition> 
      <bpmn2:timeDate xsi:type="bpmn2:tFormalExpression">2017-05-17T12:42:23Z</bpmn2:timeDate>
    </bpmn2:timerEventDefinition>
    

    An example of the XML for timeDuration is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">P5D</bpmn2:timeDuration>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a duration of 5 days.

    An example of the XML for timeCycle using time interval syntax is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle xsi:type="bpmn2:tFormalExpression">R3/PT30M</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition> 
    

    Note: This represents three repetitions every 30 minutes.

    An example of the XML for timeCycle using a cron expression is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle>0 0/5 * * * ?</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a trigger firing every 5 minutes beginning at the top of the hour.

Boundary events

Boundary events are assigned to other BPMN elements such as service tasks and user tasks. They are used by dragging the selected boundary type onto the BPMN element to influence and using the spanner icon to select the type of boundary event to use.

Whilst the element that the boundary event is attached to is being executed within a process instance, the boundary event is waiting for its trigger event. Once that event occurs the behavior can follow one of two paths:

  • Interrupting behavior where the element’s execution is terminated by the boundary event and the sequence flow out of the boundary event is followed. Interrupting boundary events are displayed as solid lines.

  • Non-interrupting behavior where the element’s execution continues and a new sequence flow is followed from the boundary event in parallel to the main sequence flow. Non-interrupting boundary events are displayed as dashed lines.

Note: Depending on the boundary type, a trigger may never reach the attached boundary event. For example a signal may not be thrown for a signal boundary event to catch.

Boundary events use the attachedToRef property to indicate the id of the element they are attached to. Interrupting behavior is the default for boundary events. Non-interrupting events contain the cancelActivity=false property.

The types of boundary event are:

Error boundary event

Error boundary events catch error events on the boundary of another element. Error boundary events are always interrupting, so as soon as an error is caught all process execution within the element they are attached to ceases.

  • Properties
  • Basic properties

    The basic properties for an error boundary event are:

    Property Description
    ID Required. The unique identifier for the error boundary event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the error boundary event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the error boundary event does.

    Error

    An error needs to be defined for the error boundary event to catch. A previously created Error can be selected from the dropdown in its properties, or a new one created using the + symbol. An Error name and Error code can then be set.

  • Error
  • Error events are used to model an exception in a business process. Errors are thrown by error end events and caught by error start events and error boundary events.

    The errorRef property in the errorEventDefinition of an error event element will match against the id of an error when viewing the XML Editor.

    Error events are displayed as a lightning bolt icon inside different shapes that differentiate between the event types. A solid lightning bolt represents a throwing event, whilst a hollow lightning bolt represents a catching event.

    To create a new error use the + symbol against an error event such as a start error event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Errors button will be visible in the right-hand properties panel.

  • Appearance
  • Error boundary events are displayed as two thin concentric circles with a hollow lightning bolt icon inside attached to the border of another BPMN element.

  • XML
  • An example of the XML of an error boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent2" attachedToRef="ServiceTask1">
    	<bpmn2:errorEventDefinition errorRef="Error_0vbkbeb" />
    </bpmn2:boundaryEvent>
    

    An example of the XML of a signal is:

    <bpmn2:error id="Error_0vbkbeb" name="payment-failed-error" errorCode="404" />
    

Message boundary event

Message boundary events are attached to the boundary of another element. When a named message is received by the message boundary event, the process flow will be interrupted or a concurrent flow will be created depending on whether the event is interrupting or non-interrupting.

  • Properties
  • Basic properties

    The basic properties for a message boundary event are:

    Property Description
    ID Required. The unique identifier for the message boundary event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the message boundary event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the message boundary event does.

    Message

    A message needs to be defined for the message boundary event to catch when it is thrown. A previously created Message can be selected from the dropdown in its properties, or a new one created using the + symbol. A Message name and payload can then be set.

  • Message
  • Message

    Messages have a name and contain a payload. They are sent by message throwing events and received by message catching events in a 1:1 relationship between throw events and catch events. Messages contain a payload known as a message payload and can be passed between scopes, for example between two different process definitions within the same diagram that are separated by different pools.

    The message id property of a message is matched against the messageRef property in the corresponding throw and catch message elements when viewing the XML Editor.

    To create a new message use the + symbol against a message event such as a message boundary event, or make sure no BPMN element is selected by clicking on a blank section of the process canvas and the Edit Messages button will be visible in the right-hand properties panel.

    Message events are displayed as an envelope icon inside different shapes that differentiate between the event types. A solid envelope represents a throwing event, whilst a hollow envelope represents a catching event.

    Message payloads

    Message payloads contain a set of values that are sent from a throwing event and received by a catching event.

    Message payloads can only be created on a message throw event and contain one or more properties that have a name, type and value. The property types for payloads are:

    Type Description
    String A sequence of characters, for example #Mint-Ice-Cream-4!
    Integer A positive whole number, for example 642
    Boolean A value of either true or false
    Date A specific date in the format YYYY-MM-DD, for example 2020-04-22
    Variable A value passed from a process variable.

    The receiving message catch event is then used to map the received values in the payload to process variables in its own scope.

    Message payload mappings can be viewed in the Extensions Editor of a process diagram. Throwing events are mapped as inputs and catching events are mapped as outputs from an event.

    Correlation keys

    Message events can optionally contain a correlation key. If a correlation key is present then when a message is thrown it uses the activiti:correlationKey value and the messageRef of the throwing event to match against the same two properties in a catching event. If only one property is matched then the message will not be caught.

    Using a process variable for the correlation key in a throwing event and a static value for its corresponding catching event allows for the message to only be caught in specific circumstances.

    Note: Message start events cannot contain a correlation key unless they are used in a sub process.

    Message flows

    When messages are used between two different pools the sequence flow that connects them is a dotted line called a message flow. The message flow is part of the collaboration element in the XML created by introducing a pool. Message flows reference the throwing message event as the sourceRef and the catching message event as the targetRef.

  • Appearance
  • Message boundary events are displayed as two thin concentric circles, or two thin dashed concentric circles, with a hollow envelope icon inside attached to the border of another BPMN element.

  • XML
  • An example of the XML of an interrupting message boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent1" attachedToRef="UserTask2">
    	<bpmn2:outgoing>SequenceFlow5</bpmn2:outgoing>
    	<bpmn2:messageEventDefinition messageRef="Message_15xakkk" />
    </bpmn2:boundaryEvent>
    

    An example of the XML of a non-interrupting message boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent3" cancelActivity="false" attachedToRef="SubProcess2">
    	<bpmn2:outgoing>SequenceFlow8</bpmn2:outgoing>
    	<bpmn2:messageEventDefinition messageRef="Message_02satcd" />
    </bpmn2:boundaryEvent>
    

    The XML representation of a message is:

    <bpmn2:message id="Message_02satcd" name="Message_02satcd" />
    

    An example of the XML of a message payload is:

        "mappings": {
            "EndEvent_0ss2fp3": {
                "inputs": {
                    "name": {
                        "type": "variable",
                        "value": "username"
                    },
                    "order-number": {
                        "type": "value",
                        "value": 1459283
                    }
                }
            }
        },
    

    An example of the XML of a message with a correlation key is:

    <bpmn2:endEvent id="EndEvent_1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:messageEventDefinition messageRef="Message_1hxecs2" activiti:correlationKey="${userId}" />
    

    In this example the message will only be caught if a catching event has a messageRef of Message_1hxecs2 and an activiti:correlationKey that matches the value of userId.

    An example of the XML of a message flow is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    	<bpmn2:messageFlow id="MessageFlow_0vh4zdb" sourceRef="Event_00acemq" targetRef="Event_13u5jtf" />
    </bpmn2:collaboration>
    

Signal boundary event

Signal boundary events can be considered catching events as they always wait to receive a named signal from a throwing event.

  • Properties
  • Basic properties

    The basic properties for a signal boundary event are:

    Property Description
    ID Required. The unique identifier for the signal boundary event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the signal boundary event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the signal boundary event does.

    Signal

    A signal needs to be defined for the signal boundary event to catch. A previously used Signal can be selected from the dropdown in its properties, or a new one created using the + symbol. A Signal name can then be set.

    Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

  • Signal
  • Signal events can be either catching or throwing. A throwing signal event will emit a signal when it is reached in a process instance that will be picked up by any catching signal event with a matching signal name. Signals can be restricted to the process instance they are thrown in, or be global in scope. The scope of a global signal is restricted to the project they are used in.

    The id of a signal will match against the signalRef of a catching or throwing event.

    Signal events are displayed as a triangle icon inside different shapes that differentiate between the event types. A solid triangle represents a throwing event, whilst a hollow triangle represents a catching event.

  • Appearance
  • Signal boundary events are displayed as two thin concentric circles with a hollow triangle icon inside attached to the border of another BPMN element.

  • XML
  • An example of the XML of a signal boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent1" attachedToRef="ServiceTask3">
          <bpmn2:signalEventDefinition signalRef="Signal_0iikg75" />
    </bpmn2:boundaryEvent>
    

    An example of the XML of a signal with a global scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" />
    

    An example of the XML of a signal with a process instance scope is:

    <bpmn2:signal id="Signal_0hnsd2r" name="Signal_0hnsd2r" activiti:scope="processInstance" />
    

Timer boundary event

Timer boundary events can be interrupting or non-interrupting. They wait for a specified time before triggering and can also be set to trigger at multiple intervals.

  • Properties
  • Basic properties

    The basic properties for a timer boundary event are:

    Property Description
    ID Required. The unique identifier for the timer boundary event. This is system generated and cannot be altered, for example IntermediateThrowEvent_1yohpmt.
    Name Optional. The name of the timer boundary event. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the timer boundary event does.

    Timer

    A choice of timer must be set for timer start events, based on a Cycle, Date or Duration.

  • Timer
  • Timer events are used to influence events at specific times, after a set amount of time has passed or at intervals. All timer events use the international standard ISO 8601 for specifying time formats.

    Note: All properties within timerEventDefinition can accept process variables as their values as long as they are in ISO 8601 or cron expression format.

    Timer events are displayed as a clock icon inside different shapes that differentiate between the event types.

    timeDate

    The timeDate property for timer events defines a specific date and time in ISO 8601 format for when the trigger will be fired and can include a specified time zone.

    The following is an example of the timerEventDefinition using a timeDate:

    • 2017-05-17 represents the 17th May 2017 in YYYY-MM-DD format
    • T12:42:23 represents the time of 12:42:23 in hh:mm:ss format
    • Z represents that the time format is in UTC (Coordinated Universal Time). The time can also contain UTC offsets such as +01 for an hour ahead of UTC. When an offset is defined the Z is not required, for example: T12:42:23+01

    timeDuration

    The timeDuration property for timer events defines how long a timer should wait in ISO 8601 format before the trigger is fired.

    The following are the letters used to refer to duration:

    Letter Description
    P Designates that the following letters and numbers represent a duration. Must always be present
    Y Represents a year and follows the number of years, for example P2Y is 2 years
    M Represents a month and follows the number of months when preceded by a P, for example P3Y4M is 2 years and 4 months
    W Represents a week and follows the number of weeks, for example P10W for 10 weeks
    D Represents a day and follows the number of days, for example P1Y1M1D for 1 year, 1 month and 1 day
    T Designates that the following letters represent a duration of hours to seconds. Must always be present to refer to hours, minutes and seconds
    H Represents an hour and follows the number of hours, for example P1DT0.5H for 1 day and half an hour
    M Represents a minute and follows the number of minutes when preceded by a T, for example PT1M for 1 minute
    S Represents a second and follows the number of seconds, for example P2Y3M4DT5H6M7S for 2 years, 3 months, 4 days, 5 hours, 6 minutes and 7 seconds

    timeCycle

    The timeCycle property for timer events defines intervals for the trigger to fire at. Intervals can be defined using the time intervals that adhere to the ISO 8601 standard or by using cron expressions.

    Time intervals

    Time intervals use the syntax R/ to set a number of repetitions, for example R5/ would repeat five times.

    Following the repetition, a duration can be set for when the repetition occurs, for example R5/PT10H would repeat every 10 hours, five times.

    Note The duration uses the same format as for timeDuration.

    An optional end date can also be set after the duration and separated by a /.

    Note: The end date uses the same format as for timeDate.

    Cron expression intervals

    Cron expressions can also be used to define repeating triggers for timer events.

  • Appearance
  • Timer boundary events are displayed as two thin concentric circles, or two thin dashed concentric circles, with a clock icon inside attached to the border of another BPMN element.

  • XML
  • An example of the XML of an interrupting timer boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent3" attachedToRef="UserTask1">
    	<bpmn2:outgoing>SequenceFlow5</bpmn2:outgoing>
    	<bpmn2:timerEventDefinition>
    		<bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">PT10M</bpmn2:timeDuration>
    	</bpmn2:timerEventDefinition>
    </bpmn2:boundaryEvent>
    

    An example of the XML of a non-interrupting timer boundary events is:

    <bpmn2:boundaryEvent id="BoundaryEvent4" cancelActivity="false" attachedToRef="SubProcess1">
    	<bpmn2:outgoing>SequenceFlow8</bpmn2:outgoing>
    	<bpmn2:timerEventDefinition>
    		<bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">P5D</bpmn2:timeDuration>
    	</bpmn2:timerEventDefinition>
    </bpmn2:boundaryEvent>
    

    An example of the XML for timeDate is:

    <bpmn2:timerEventDefinition> 
      <bpmn2:timeDate xsi:type="bpmn2:tFormalExpression">2017-05-17T12:42:23Z</bpmn2:timeDate>
    </bpmn2:timerEventDefinition>
    

    An example of the XML for timeDuration is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeDuration xsi:type="bpmn2:tFormalExpression">P5D</bpmn2:timeDuration>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a duration of 5 days.

    An example of the XML for timeCycle using time interval syntax is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle xsi:type="bpmn2:tFormalExpression">R3/PT30M</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition> 
    

    Note: This represents three repetitions every 30 minutes.

    An example of the XML for timeCycle using a cron expression is:

    <bpmn2:timerEventDefinition>
      <bpmn2:timeCycle>0 0/5 * * * ?</bpmn2:timeCycle>
    </bpmn2:timerEventDefinition>
    

    Note: This represents a trigger firing every 5 minutes beginning at the top of the hour.

Gateways

Gateways are used to deal with convergence and divergence of the process flow. They allow for more than one fork of a process to be followed, or they can evaluate conditions so that a different route may be followed for each specific set of circumstances.

The types of gateway are:

Exclusive gateway

Exclusive gateways represent a decision within a process.

Once the process flow reaches an exclusive gateway, all of the outgoing sequence flow options are evaluated in the order they are defined. The first option that evaluates to true is the sequence flow that is followed. A default sequence flow can be set incase none of the outgoing sequence flows evaluate to true.

  • Properties
  • Basic properties

    The basic properties for an exclusive gateway are:

    Property Description
    ID Required. The unique identifier for the exclusive gateway. This is system generated and cannot be altered, for example Gateway_1ppp31l.
    Name Optional. The name of the exclusive gateway. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the exclusive gateway does.

    Default sequence flow

    The name of a sequence flow can be used to select a default flow for the gateway to take. This path will be followed if none of the other sequence flows evaluate to true. Conditional expressions can be configured on sequence flows to select which path is taken.

  • Appearance
  • Exclusive gateways are displayed as a single thin diamond shape with an X icon inside.

    Note: A single thin diamond on its own defaults to an exclusive gateway, however the BPMN specification does not allow diamonds with, and without, an X in the same process definition.

  • XML
  • An example of the XML of an exclusive gateway is:

    <bpmn2:exclusiveGateway id="ExclusiveGateway_1" name="Content Accepted?" default="SequenceFlow_2">
    	<bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_2</bpmn2:outgoing>
    	<bpmn2:outgoing>SequenceFlow_3</bpmn2:outgoing>
    </bpmn2:exclusiveGateway>
        <bpmn2:sequenceFlow id="SequenceFlow_1" sourceRef="Task_1" targetRef="ExclusiveGateway_1" />
        <bpmn2:sequenceFlow id="SequenceFlow_2" name="yes" sourceRef="ExclusiveGateway_1" targetRef="Task_2">
    		<bpmn2:conditionExpression xsi:type="bpmn:tFormalExpression">${content.approved == true}</bpmn2:conditionExpression>
    	</bpmn2:sequenceFlow>
        <bpmn2:sequenceFlow id="SequenceFlow_3" name="no" sourceRef="ExclusiveGateway_1" targetRef="Task_3">
    		<bpmn2:conditionExpression xsi:type="bpmn:tFormalExpression">${content.approved == false}</bpmn2:conditionExpression>
        </bpmn2:sequenceFlow>
    

Inclusive gateway

Inclusive gateways allow for convergence and divergence in a process, however they also allow for conditional sequence flows.

Once the process flow reaches an inclusive gateway, all of the outgoing sequence flows are evaluated and all flows that evaluate to true are followed for divergent behavior. A default sequence flow can be set incase none of the outgoing sequence flows evaluate to true.

For a converging inclusive gateway, the process waits until all active sequence flows reach the gateway before continuing.

  • Properties
  • Basic properties

    The basic properties for an inclusive gateway are:

    Property Description
    ID Required. The unique identifier for the inclusive gateway. This is system generated and cannot be altered, for example Gateway_1ppp31l.
    Name Optional. The name of the inclusive gateway. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the inclusive gateway does.

    Default sequence flow

    The name of a sequence flow can be used to select a default flow for the gateway to take. This path will be followed if none of the other sequence flows evaluate to true. Conditional expressions can be configured on sequence flows to select which path is taken.

  • Appearance
  • Inclusive gateways are displayed as a single thin diamond shape with a circle inside.

  • XML
  • An example of the XML of an inclusive gateway is:

    <bpmn2:inclusiveGateway id="InclusiveGateway_1" name="Content Metadata" default="SequenceFlow_2">
    	<bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_2</bpmn2:outgoing>
    	<bpmn2:outgoing>SequenceFlow_3</bpmn2:outgoing>
    </bpmn2:inclusiveGateway>
        <bpmn2:sequenceFlow id="SequenceFlow_1" sourceRef="Task_1" targetRef="InclusiveGateway_1" />
        <bpmn2:sequenceFlow id="SequenceFlow_2" name="yes" sourceRef="InclusiveGateway_1" targetRef="Task_2">
    		<bpmn2:conditionExpression xsi:type="bpmn:tFormalExpression">${content.size == "A4"}</bpmn2:conditionExpression>
    	</bpmn2:sequenceFlow>
        <bpmn2:sequenceFlow id="SequenceFlow_3" name="no" sourceRef="InclusiveGateway_1" targetRef="Task_3">
    		<bpmn2:conditionExpression xsi:type="bpmn:tFormalExpression">${content.origin == "Email"}</bpmn2:conditionExpression>
        </bpmn2:sequenceFlow>
    

Parallel gateway

Parallel gateways represent a concurrent convergence or divergence in a process.

Divergence means that all sequence flows exiting a parallel gateway are executed concurrently. A converging parallel gateway waits for all concurrent sequence flows to arrive at the gateway, before continuing with the process.

Parallel gateways do not evaluate conditions. Any conditions set on a sequence flow will be ignored by the parallel gateway.

Note: It is possible for a single parallel gateway to execute both converging and diverging behavior.

  • Properties
  • Basic properties

    The basic properties for a parallel gateway are:

    Property Description
    ID Required. The unique identifier for the parallel gateway. This is system generated and cannot be altered, for example Gateway_1ppp31l.
    Name Optional. The name of the parallel gateway. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the parallel gateway does.
  • Appearance
  • Parallel gateways are displayed as a single thin diamond shape with a + icon inside.

  • XML
  • An example of the XML of a parallel gateway is:

    <bpmn2:parallelGateway id="Fork_1">
    	<bpmn2:sequenceFlow id="SequenceFlow_1" sourceRef="Fork_1" targetRef="UserTask_1" />
     	</bpmn2:sequenceFlow>
     	<bpmn2:sequenceFlow id="SequenceFlow_2" sourceRef="Fork_1" targetRef="ServiceTask_1" />
     	</bpmn2:sequenceFlow>
    </bpmn2:parallelGateway>
    

Tasks

Tasks are used in a process to include other models from a project in a process.

The types of task are:

Business rule task

Business rule tasks are used to include decision tables in a process definition.

Business rule tasks are essentially treated as service tasks and will always have the implementation value of dmn-connector.EXECTUTE_TABLE. The name of the decision table that is associated to the business rule task is used as the value under _activiti_dmn_table_ when viewing the Extensions Editor.

  • Properties
  • Basic properties

    The basic properties for a business rule task are:

    Property Description
    ID Required. The unique identifier for the business rule task. This is system generated and cannot be altered, for example ServiceTask_0a1cgxd.
    Name Optional. The name of the business rule task. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the business rule task does.

    Multi-instance type

    Business rule tasks can be set to repeat sequentially or in parallel when the process flow reaches them.

    Decision table name

    The name of the decision table to use. The decision table must exist within the same project as the process definition to be selected. Select a decision table from the dropdown, else create a new one using the + symbol.

    Mapping type

    The mapping type sets how data is passed between the decision table and the process. There are five options for how to send this data. The default value is Send no variables.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Business rule tasks are displayed as a single, thin rounded rectangle with a table icon inside.

  • XML
  • An example of the XML of a business rule task is:

    <bpmn2:serviceTask id="ServiceTask_4" implementation="dmn-connector.EXECUTE_TABLE" />
    

    An example of the Extensions Editor JSON of a process containing a business rule task is:

    "constants": {
    	"ServiceTask_2f85xew": {
    		"_activiti_dmn_table_": {
    			"value": "my-decision-table-1"
                }
            }
        },
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Script task

Script tasks are used to include scripts in a process definition.

Script tasks are essentially treated as service tasks and will always have the implementation value of script.EXECUTE. The name of the script that is associated to the script task is used as the value under _activiti_script_ when viewing the Extensions Editor.

  • Properties
  • Basic properties

    The basic properties for a script task are:

    Property Description
    ID Required. The unique identifier for the script task. This is system generated and cannot be altered, for example ServiceTask_0a1cgxd.
    Name Optional. The name of the script task. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the script task does.

    Multi-instance type

    Script tasks can be set to repeat sequentially or in parallel when the process flow reaches them.

    Script name

    The name of the script to use. The script must exist within the same project as the process definition to be selected. Select a script from the dropdown, else create a new one using the + symbol.

    Mapping type

    The mapping type sets how data is passed between the script and the process. There are five options for how to send this data. The default value is Send no variables.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Script tasks are displayed as a single thin, rounded rectangle with a script icon inside.

  • XML
  • An example of the XML of a script task is:

    <bpmn2:serviceTask id="Task_0gpdh83" name="Order script" implementation="script.EXECUTE">
    	<bpmn2:documentation>A script to loop and update the list of orders.</bpmn2:documentation>
    </bpmn2:serviceTask>
    

    An example of the Extensions Editor JSON of a process containing a script task is:

        "constants": {
            "Task_0ykbcv0": {
                "_activiti_script_": {
                    "value": "order-script"
                }
            }
        }
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Service task

Service tasks are used to include connectors, business rule tasks and script tasks in a process.

Note: Service tasks do not emit the TASK_CREATED and TASK_COMPLETED events. The INTEGRATION_REQUESTED and INTEGRATION_RESULT_RECEIVED events should be monitored to report or track service tasks instead.

  • Properties
  • Basic properties

    The basic properties for a service task are:

    Property Description
    ID Required. The unique identifier for the service task. This is system generated and cannot be altered, for example ServiceTask_0a1cgxd.
    Name Optional. The name of the service task. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the service task does.

    Multi-instance type

    Script tasks can be set to repeat sequentially or in parallel when the process flow reaches them.

    Implementation

    The implementation value is used to associate a connector with a service task. For business rule tasks and script tasks this value is set by default and cannot be changed. The format is <connector-name>.<connector-action>.

    Action

    An action selects which of the connector actions that service task should execute, for example whether to send a message or create a new channel in Slack when using the Slack connector.

    Mapping type

    The mapping type sets how data is passed between the connector and the process. There are five options for how to send this data. The default value is Send no variables.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Service tasks are displayed as a single, thin rounded rectangle with a cog icon inside.

  • XML
  • An example of the XML of a service task is:

    <bpmn2:serviceTask id="Task_19x7wuh" name="send-email" implementation="email-connector.SEND">
    	<bpmn2:documentation>A connector that sends an email.</bpmn2:documentation>
    	<bpmn2:incoming>SequenceFlow_19fgs1w</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_64jaw7e</bpmn2:outgoing>
    </bpmn2:serviceTask>
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

User task

User tasks represent a stage in the process where human action is required.

Human action is handled by a task being assigned to specific users or groups. The task that is assigned can be modeled using a form. Once a task is completed, the process flow continues on to the next element in the process.

  • Properties
  • Basic properties

    The basic properties for a user task are:

    Property Description
    ID Required. The unique identifier for the user task. This is system generated and cannot be altered, for example UserTask_0w526j8.
    Name Optional. The name of the user task. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the user task does.

    Assignment

    The users or groups that are able to complete a task. A single user can be assigned or candidates can be set. Candidates are a list of users or groups that may claim a task at runtime. A single user or candidates must be set for a user task.

    A single assignee is set in the XML attribute activiti:assignee and candidates in the attribute activiti:candidateGroups.

    Users and groups can be set from three different sources:

    • Static values are a free text field that has no validation as to whether a user exists or not. The text entered will require an exact match to a username in the product environment for the user task to be correctly assigned at runtime.

    • Identity allows for users and groups to be searched for and selected for the assignment. The users and groups must exist whilst modeling to display in this list.

    • Expression allows for an expression using process variables to be used to select users and groups for the assignment. Expressions can be a simple process variable such as ${userToAssign} or an expression such as ${userDetails.username} that uses a process variable of type JSON. A JSON editor is provided for creating expressions for assignment, however the editor will only be displayed if there are process variables in the process.

      Note: The value "assignee": "${initiator}" can be set as an expression without creating a process variable. This will assign the task to the user that started the process instance.

    The assignments for user tasks are stored in the assignments property of the Extensions Editor.

    Note: Users and groups that are selected as assignees or candidates in a user task are automatically added as users when deploying an application if they are set using the static or identity options. Setting an assignee or candidate using the expression source will require the potential users or groups to be manually assigned users when deploying an application.

    Due date

    An optional date and time for a user task to be completed by in ISO 8601 format. A date picker can be used to choose the time and date.

    Checking the Use process variable box for due date allows a process variable to be used to generate the date. The process variable must be of type datetime.

    Multi-instance type

    Script tasks can be set to repeat sequentially or in parallel when the process flow reaches them.

    Priority

    An optional priority for the user task between 0 and 4. The priority property is to aid end users in their task management.

    Form name

    A form can be assigned to the user task. The form must exist within the same project as the process definition to be selected. Select a form from the dropdown, else create a new form using the + symbol.

    Once a form has been selected, it can be edited using the Open Form symbol.

    Mapping type

    The mapping type sets how data is passed between the user task and the process. There are five options for how to send this data. The default value is Send no variables.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • User tasks are displayed as a single thin, rounded rectangle with a user icon inside.

  • XML
  • An example of the XML of a user task is:

    <bpmn2:userTask id="UserTask_0gpdh83" name="Order" activiti:formKey="form-38098a3e-bff1-46cb-ba0f-0c94fdb287ed" activiti:assignee="${userDetails.username}" activiti:dueDate="2020-01-01T01:00:00" activiti:priority="2">
    	<bpmn2:documentation>A form to choose the flavor of ice cream.</bpmn2:documentation>
    	<bpmn2:incoming>SequenceFlow_02eaofe</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_14ma5mo</bpmn2:outgoing>
    </bpmn2:userTask>
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Sub-processes and call activities

Sub-processes and call activities are used to define separate processes. Sub-processes are defined and executed within the same process definition as the parent process, whilst call activities start a completely separate process.

The types of sub-process are:

Call activity

Call activities are used to start an instance of another process definition. The original process waits until the called process is complete before continuing with its own process flow.

The calledElement property uses a processDefinitionId to define which process to start.

Note: When a call activity element is executed it receives its own processInstanceId. The process variables of a call activity are also completely separate to those in the parent process.

Note: Call activities can only be used to start a process instance of a process definition that exists in the same application as the process that is calling it.

  • Properties
  • Basic properties

    The basic properties for a call activity are:

    Property Description
    ID Required. The unique identifier for the call activity. This is system generated and cannot be altered, for example CallActivity_1kb3t8n.
    Name Optional. The name of the call activity. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the call activity does.

    Multi-instance type

    Sub-processes can be set to repeat sequentially or in parallel when the process flow reaches them.

    Called element

    The process definition the call activity should start is set using the called element property.

    The called element can be set in two ways:

    • Static values select a process definition name from a dropdown list.

    • Expression values allow an expression to be set to dynamically call a process definition based on an expression or process variable.

    Mapping type

    The mapping type sets how data is passed between the parent process and the process being started by the call activity. There are five options for how to send this data. The default value is Send no variables.

    Note: if an Expression is used to set which process definition to call in the call element property, it is not possible to explicitly map the variable exchange in the mapping type.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Call activities are displayed as a single, thick rounded rectangle without an icon inside.

  • XML
  • An example of the XML of a call activity is:

    <bpmn2:callActivity id="Task_5" name="Start request process" calledElement="process-a6d6ca00-cbb6-45d6-ae24-50ef53d37cc4">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_9</bpmn2:outgoing>
    </bpmn2:callActivity>
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Expanded and collapsed sub-processes

Sub-processes are also known as embedded sub-processes and can be expanded or collapsed. Elements for the sub-process can only be dragged into an expanded sub-process. Use the spanner icon against a sub-process to toggle between a collapsed and expanded state.

A sub-process requires a start and an end event. Only a standard start event can be used in embedded sub-processes. The sequence flow within a sub-process cannot cross its boundary without the sub-process completing. The advantage of a sub-process is that it creates its own scope within a process. This allows for boundary events to be attached to the sub-process.

Note: When a sub-process is executed as part of a process instance, it does not receive a new processInstanceId. The elements within the sub-process will be executed under the ID of the parent process. Process variables are also shared between a sub-process and its parent with no additional mapping required.

  • Properties
  • Basic properties

    The basic properties for a sub-process are:

    Property Description
    ID Required. The unique identifier for the sub-process. This is system generated and cannot be altered, for example CallActivity_1kb3t8n.
    Name Optional. The name of the sub-process. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the sub-process does.

    Multi-instance type

    Sub-processes can be set to repeat sequentially or in parallel when the process flow reaches them.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Whilst expanded, sub-processes are displayed as a single, thin rounded rectangle with the other BPMN elements they contain visible.

    Whilst collapsed, sub-processes are displayed as a single, thin rounded rectangle with a + symbol. The BPMN elements they contain are not visible in this state.

  • XML
  • An example of the XML of a sub-process is:

    <bpmn2:subProcess id="SubProcess1">
    	<bpmn2:incoming>SequenceFlow_8</bpmn2:incoming>
    	<bpmn2:outgoing>SequenceFlow_9</bpmn2:outgoing>
    	...
    </bpmn2:subProcess>
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Event sub-processes

Event sub-processes are triggered by an event such as a signal or error and require a start and end event. As they are triggered by events an event sub-process can’t be started by a standard start event. Instead start events such as error start events or message start events are used.

Event sub-processes are not connected to the main process flow as they can only be triggered by an event. The XML for an event sub-process contains the triggeredByEvent property set to true.

Event sub-processes can be placed at the process level or inside a sub-process.

Note: When an event sub-process is executed as part of a process instance, it does not receive a new processInstanceId. The elements within the event sub-process will be executed under the ID of the parent process. Process variables are also shared between an event sub-process and its parent with no additional mapping required.

  • Properties
  • Basic properties

    The basic properties for an event sub-process are:

    Property Description
    ID Required. The unique identifier for the event sub-process. This is system generated and cannot be altered, for example CallActivity_1kb3t8n.
    Name Optional. The name of the event sub-process. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the event sub-process does.

    Multi-instance type

    Sub-processes can be set to repeat sequentially or in parallel when the process flow reaches them.

  • Multi-instance
  • Multi-instance allows for the element to be repeated within a process. There are two options for how to execute multi-instance elements: sequentially or in parallel.

    • Sequential executions only ever have a single instance running at any one time. The next instance will only start after the previous one has been completed.

    • Parallel executions start all instances at once, meaning they are all active and can all be worked on at the same time.

    Multi instance elements are displayed as three parallel lines at the bottom of the original element. Sequential lines are horizontal and parallel lines are vertical.

    Variables

    Each multi-instance execution has three variables:

    Variable Description
    nrOfInstances The total number of instances
    nrOfActiveInstances The number of currently active instances. For sequential multi-instances the value will always be 1
    nrOfCompletedInstances The number of instances that have already been completed

    Note: These variables can be used in multi-instance expressions without having to be declared as process variables.

    Each instance in the multi-instance execution also has an instance-local variable that is not visible to other instances, nor to the process instance:

    Variable Description
    loopCounter The index in the for-each loop of that particular instance

    Cardinality

    Cardinality sets the number of instances to be executed by the multi-instance element. This can be set as a static value, a process variable or calculated as an expression.

    Collection

    A collection can be used to set the number of instances to be executed by referencing a list of items.

    An element variable can optionally be used with a collection. An element variable is used to create a variable for each instance of the multi-instance element and each variable created by the element variable is assigned one value from the collection.

    Completion condition

    A completion condition can optionally be included for multi-instances. When the completion condition evaluates to true, all remaining instances are cancelled and the multi-instance activity ends.

    Results

    A result collection can be set to aggregate the results from each instance into a variable. The result collection is created as a process variable after instance execution has finished.

    The result element variable is used to select the field or variable from the BPMN element to aggregate into the result collection.

  • Appearance
  • Event sub-processes are displayed as a single, thin dotted rectangle.

  • XML
  • An example of the XML of an event sub-process is:

    <bpmn2:subProcess id="EventSubProcess2" triggeredByEvent="true">
    	...
    </bpmn2:subProcess>
    

    An example of the XML for an element that contains sequential multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics isSequential="true" />
    

    An example of the XML for an element that contains parallel multi-instance elements is:

    <bpmn2:multiInstanceLoopCharacteristics  isSequential="false" />
    

    or

    <bpmn2:multiInstanceLoopCharacteristics />
    
    

    An example of the XML of multi-instance cardinality is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>5</bpmn2:loopCardinality>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    An example of the XML of a multi-instance collection is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${user}">
    	<bpmn2:incoming>SequenceFlow_5</bpmn2:incoming>
    	<bpmn2:multiInstanceLoopCharacteristics activiti:collection="${userList.users}" activiti:elementVariable="user">
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The activiti:collection references a process variable called userList that contains the following JSON:

    {"users":["user1", "user2", "user3"]}
    

    In the example:

    • Three user tasks will be created because there are three items in the process variable that activiti:collection uses.
    • A variable will be created for each instance called users with the values user1, user2 and user3 because the activiti:elementVariable is set to "users".
    • A user tasks will be assigned to each of the users because the activiti:assignee is set to {users} which is the name of the variable created in each instance by the element variable.

    An example of the XML of a multi-instance completion condition is:

    <bpmn2:multiInstanceLoopCharacteristics>
    	<bpmn2:loopCardinality>10</bpmn2:loopCardinality>
    	<bpmn2:completionCondition>${nrOfCompletedInstances/nrOfInstances >= 0.6 }</bpmn2:completionCondition>
    </bpmn2:multiInstanceLoopCharacteristics>
    

    Note: The completion condition will be met when 60% of instances have been completed and the remaining 4 instances will be cancelled.

    An example of the XML of a multi-instance element is:

    <bpmn2:userTask id="UserTask_1n1uk4a" activiti:assignee="${users}">
    	<bpmn2:multiInstanceLoopCharacteristics isSequential="true">
    		<bpmn2:loopCardinality>4</bpmn2:loopCardinality>
    		<bpmn2:loopDataOutputRef>choices</bpmn2:loopDataOutputRef>
    		<bpmn2:outputDataItem name="flavor" />
    	</bpmn2:multiInstanceLoopCharacteristics>
    </bpmn2:userTask>
    

    Note: The user task will run 4 times sequentially and the values of flavor from the form will be stored as a JSON object in the variable choices. The process variable choices will contain a list of results similar to the following:

    ["chocolate", "mint", "strawberry"]
    

Sequence flows, pools and lanes

Sequence flows represent the direction of flow in a process, whilst pools and lanes are used to model different participants, personas and process definitions in the same diagram.

Sequence flow

Sequence flows represent the direction of flow in a process. The can be drawn between BPMN elements using the Global connect tool.

  • Properties
  • Basic properties

    The basic properties for a sequence flow are:

    Property Description
    ID Required. The unique identifier for the sequence flow. This is system generated and cannot be altered, for example SequenceFlow_1y8xkql.
    Name Optional. The name of the sequence flow. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the sequence flow does.

    Condition expression

    A condition expression can be set when a sequence flow is connected to an inclusive or exclusive gateway. Conditions will be evaluated to decide whether a path is taken or not. The expression syntax can reference process variables using expressions such as ${content.approved} == false} where that path will be taken if the approved attribute of the variable content is set to false.

    Another example of conditional expressions when evaluating a sequence flow is using amounts, for example ${amount>500} will take the sequence flow if the process variable amount is greater than 500 at the point the gateway is reached.

  • Appearance
  • Sequence flows are displayed as single black lines with an arrow indicating the direction of flow.

  • XML
  • An example of the XML of a sequence flow is:

    <bpmn2:incoming>SequenceFlow_1</bpmn2:incoming>
    <bpmn2:outgoing>SequenceFlow_2</bpmn2:outgoing>
    

    An example of the XML of a sequence flow with a condition expression set is:

    <bpmn2:sequenceFlow id="SequenceFlow_1" name="no" sourceRef="ExclusiveGateway_1" targetRef="Task_1">
    	<bpmn2conditionExpression xsi:type="bpmn:tFormalExpression">${content.approved == false}</bpmn2:conditionExpression>
    </bpmn2:sequenceFlow>
    

Pools and lanes

Pools allow multiple process definitions to be modeled in a single diagram, or to utilize lanes to show the personas interacting with a process defintion. An example of using two pools would be for a customer to fill out an order in one process definition that sends a message on order completion triggering a second process defintion for a warehouse team to action. The two processes would have two completely different process instance IDs at runtime but can be modeled on the same diagram to capture the business process in a single location.

Lanes are used to display different personas interacting with a process definition to the modeler. They have no impact on a process at runtime. Lanes are sub-divisions of pools and cannot exist without them. They can also be nested for example to show different teams within a department.

Important: The scope of process variables are restricted to each process definition.

  • Pools
  • Basic properties

    The basic properties for a pool are:

    Property Description
    ID Required. The unique identifier for the pool. This is system generated and cannot be altered, for example Participant_0efla7f.
    Documentation Optional. A free text description of what the pool does.

    Note: Pools use the process definition name rather than having an additional name property.

  • Lanes
  • Basic properties

    The basic properties for a lane are:

    Property Description
    ID Required. The unique identifier for the lane. This is system generated and cannot be altered, for example Lane_1ikh7j5.
    Name Optional. The name of the lane. This will be displayed on the canvas.
    Documentation Optional. A free text description of what the lane does.
  • XML
  • An example of the XML of a pool is:

    <bpmn2:collaboration id="Collaboration_0kgbwi1">
    	<bpmn2:participant id="Participant_1i6u1my" processRef="Process_1d9yxsm" />
    	<bpmn2:participant id="Participant_10umhbc" processRef="Process_1piiyp4" />
    </bpmn2:collaboration>
    

    An example of the XML of a lane is:

    <bpmn2:process id="Process_1d9yxsm">
    	<bpmn2:laneSet id="LaneSet_1b8nhx7">
    		<bpmn2:lane id="Lane_104t61m" name="HR Department">
    			<bpmn2:flowNodeRef>Event_0b61hqt</bpmn2:flowNodeRef>
    			<bpmn2:flowNodeRef>Gateway_1dmrhcn</bpmn2:flowNodeRef>
    		</bpmn2:lane>
    		<bpmn2:lane id="Lane_1i3x8rz" name="Finance Department">
    			<bpmn2:flowNodeRef>Task_16ju082</bpmn2:flowNodeRef>
    			<bpmn2:flowNodeRef>Event_00acemq</bpmn2:flowNodeRef>
    		</bpmn2:lane>
    </bpmn2:laneSet>
    

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