Essential Business Process Modeling

Additional Patterns

As discussed previously, the P4 patterns are oriented towards control flow. Control flow is only one aspect of process design; the designer can also benefit from patterns describing how to communicate with external partners (communication patterns), and how to manage recurring human workflow scenarios (human workflow patterns).

Communication Patterns

Figure 4-32 illustrates a variety of common communication scenarios in a process.

Figure 4-32. Various communication patterns

The diagram reveals a number of common patterns:

Receive Request

A process triggered by an inbound service request, as indicated by A in the figure. In BPEL, the pattern is implemented with the receive activity. If the caller expects a synchronous response, use the reply activity.

Call Partner Service

A process sends a message to the partner’s service. In BPEL, the pattern is implemented in with the invoke activity. Synchronous and asynchronous variants are supported, as in the two steps labeled B in the diagram.

Wait for Response

A process explicitly waits for a specific event or set of events, as in the step labeled C in the diagram. In BPEL, implement using an intermediate receive or pick.

Unsolicited Event

A process responds to an unexpected event (e.g., cancellation request), as in the step labeled D of the diagram. In BPEL, implement using an eventHandler.

Correlate Request and Response

A process filters ...