User Task:

User tasks must be completed by process participants and are associated with Human services by default.

For cases where you want a user to start the service but no additional user involvement is required, you can also choose a user task type and associate a service with it, such as an Integration or Advanced Integration service.

Process Designer automatically creates the required user implementation that you need when you DRAG process components onto a diagram. You can also choose User Task and an associated service for an activity implementation, as described in IMPLEMENTING activities.

System Task:

System tasks must be completed by an automated system or service and are automatically run without a need for user INITIATION regardless of the type of lane in which they are defined in a BPD diagram.

When you drag an Ajax service, General System service, Integration service, or Advanced Integration service from the library to a BPD diagram, Process Designer automatically creates an activity with a System task type, regardless of WHETHER the service is dragged to a system lane or to a participant lane.

Dragging an activity from the palette to a system lane in a BPD diagram automatically creates an activity with a System task with the Default System service selected. System tasks that you place in a non-system lane are also run by the system.

Decision Task:

Decision tasks are useful when you want a decision or condition in a business rule to determine which process implementation is started.

When you drag a Decision service from the library to a BPD diagram, Process Designer automatically creates an activity with a Decision task.

User Task:

User tasks must be completed by process participants and are associated with Human services by default.

For cases where you want a user to start the service but no additional user involvement is required, you can also choose a user task type and associate a service with it, such as an Integration or Advanced Integration service.

Process Designer automatically creates the required user implementation that you need when you drag process components onto a diagram. You can also choose User Task and an associated service for an activity implementation, as described in Implementing activities.

System Task:

System tasks must be completed by an automated system or service and are automatically run without a need for user initiation regardless of the type of lane in which they are defined in a BPD diagram.

When you drag an Ajax service, General System service, Integration service, or Advanced Integration service from the library to a BPD diagram, Process Designer automatically creates an activity with a System task type, regardless of whether the service is dragged to a system lane or to a participant lane.

Dragging an activity from the palette to a system lane in a BPD diagram automatically creates an activity with a System task with the Default System service selected. System tasks that you place in a non-system lane are also run by the system.

Decision Task:

Decision tasks are useful when you want a decision or condition in a business rule to determine which process implementation is started.

When you drag a Decision service from the library to a BPD diagram, Process Designer automatically creates an activity with a Decision task.