There are a number of tools you will need to design, execute, and monitor your workflows. Some of these are included with Alfresco, and some you can obtain separately.
You create an Activiti process definition in Alfresco using the BPMN 2.0 standard.
The task model is a description of each task in a workflow. It defines attributes associated with that task. A user interface component can use this description to automatically generate an interface suitable for displaying the task information, in addition to initializing a newly created task instance.
Setting up Activiti Designer
To create Activiti process definitions using a graphical user interface you will need to set up the Activiti designer.
Deploying the task model
You deploy your workflow task model using the Spring "Workflow Deployer" bean. The bean can be used in conjunction with Alfresco's configuration extension mechanism to deploy custom made workflows and models.
Deploying a process definition
You can deploy a process definition from the Activiti workflow console or you can deploy it manually using a spring bean.