Activities (BPMN)

Activities are work that is performed within a process. You can create activities in collaboration and process diagrams.

The following types of activities are available:

Symbol	Description
	Abstract task - Basic unit of work.
	Send task - Sends a message to a participant external to the process. Once the message has been sent, the task is completed.
	Receive task - Waits for a message to arrive from a participant external to the process. Once the message has been received, the task is completed.
	User task - A human performer performs the task with the assistance of a software application and is scheduled through a task list manager of some sort.
	Manual task - A task that is performed without the aid of any business process execution engine or any application. For example, a telephone technician installing a telephone at a customer location.
	Business rule task - Sends input to a business rules engine and receives the output of the engine's calculations.
	Service task - Uses a Web service or automated application.
	Script task - Executed by a script interpreted by a business process engine.
	Transaction - Set of activities that logically belong together, and which might follow a specific transaction protocol.
	Call activity - Wrapper for a globally defined sub-process or task that is reused in the current process.
	Sub-process - An activity whose internal details have been modeled using activities, gateways, events, and sequence flows.
	Event sub-process - Placed into a process or sub-process and is activated when its start event is triggered, and can interrupt the higher level process context or run in parallel (non-interrupting) depending on the start event.
	Ad hoc sub-process - A specialized type of sub-process that is a group of activities that have no required sequence relationships, and whose sequence and number are determined by the performers of the activities.

Activities are based upon and share the properties of standard BPM processes (see Processes (BPM)). They can be decomposed and contain their own collaboration diagrams in the same way as processes (see Decomposing Processes).