Parallel Split Pattern in modeling -BASIC PATTERNS

Parallel split

After the analysis made in the basic pattern called sequence which is the most basic step in modeling and processes, we should move on to the parallel split. The intent of the parallel split pattern is to branch, or fork from a single activity to multiple parallel paths. This Pattern is also known as AND-split.

It occurs when there is a need of multiple streams to execute at the same time. An example of this would be when an employee needs to apply for vacation. The Department manager gets the application of the employee. At the same time the application is forwarded to HR dept. where the HR employee should update the available dates. The application approval depends on the Department manager and the HR. to let the process move on to its completion these to tasks should complete successfully.

This pattern is related to Synchronization, Exclusive Choice and Multi-Choice

Synchronization

the intent of synchronization pattern is to have several parallel paths converge on a single activity which waits for the completion of all paths before starting. The pattern is also known as AND-Join. Synchronization is common requirement for many processes. In the above example to get the process of work permit completed the activity of final completion from the department responsible for work permits must not be started until the 2 preceding parallel activities have completed.

In languages in which parallel processing is modeled as a control structure(flow in BPEL and ALL in BPMN) the control structure itself manages the merge. For example, in BPEL when the flow in BPEL completes, its child activities are guaranteed to have completed. In languages where the merge requires an explicit join element(such as the AND gateway in BPMN and the join in UML activity diagrams) the join element performs the merge.

This pattern is related to parallel split, Simple Merge, Synchronizing Merge,Multi-Merge, Discriminator