IBM BPM, V8.0.1, All platforms > Programming IBM BPM > Developing client applications for BPEL processes and tasks > Developing EJB client applications

Developing applications for BPEL processes and human tasks

People are involved in most business process scenarios.

For example, a business process requires people interaction when the process is started or administered, or when human task activities are performed. To support these scenarios, you need to use both the Business Flow Manager API and the Human Task Manager API.

To involve people in business process scenarios, you can include the following task kinds in the BPEL process:

• An inline invocation task (also known as an originating task in the API).

  You can provide an invocation task for every receive activity, for each onMessage element of a pick activity, and for each onEvent element of an event handler. This task then controls who is authorized to start a process or communicate with a running process instance.

• An administration task.

  You can provide an administration task to specify who is authorized to administer the process or perform administrative operations on the failed activities of the process.

• A to-do task (also known as a participating task in the API).

  A to-do task implements a human task activity. This type of activity allows you to involve people in the process.

Human task activities in the business process represent the to-do tasks that people perform in the business process scenario.

You can use both the Business Flow Manager API and the Human Task Manager API to realize these scenarios:

• The business process is the container for all of the activities that belong to the process, including the human task activities that are represented by to-do tasks. When a process instance is created, a unique object ID (PIID) is assigned.

• When a human task activity is activated during the execution of the process instance, an activity instance is created, which is identified by its unique object ID (AIID). At the same time, an inline to-do task instance is also created, which is identified by its object ID (TKIID). The relationship of the human task activity to the task instance is achieved by using the object IDs:

  • The to-do task ID of the activity instance is set to the TKIID of the associated to-do task.

  • The containment context ID of the task instance is set to the PIID of the process instance that contains the associated activity instance.

  • The parent context ID of the task instance is set to the AIID of the associated activity instance.

• The lifecycles of all inline to-do task instances are managed by the process instance. When the process instance is deleted, then the task instances are also deleted.

  For example, all of the tasks that have the containment context ID set to the PIID of the process instance are automatically deleted.

• Determining the BPEL process templates or activities that can be started
  A BPEL process can be started by invoking the call, initiate, or sendMessage methods of the Business Flow Manager API. If the process has only one starting activity, you can use the method signature that requires a process template name as a parameter. If the process has more than one starting activity, you must explicitly identify the starting activity.
• Processing a page flow that is started by a to-do task
  Some workflows are performed by only one person, for example, ordering books from an online bookstore. This example shows how to use both the Business Flow Manager and the Human Task Manager APIs are to process this type of workflow.

Developing EJB client applications for BPEL processes and human tasks