Parallel shape in BizTalk is most confusing shape in Orchestration toolbox. I am going to give an example of parallel shape for removing this confusion.
What does Parallel shape in BizTalk do ?
Parallel shape in BizTalk is NOT used for concurrent processing. The Parallel shape enables you to complete different stages of business process without having to wait for another part of the business process to complete. It does not provide a separate thread per branch.
I have created an orchestration with a parallel shape which have 3 branches containing 3 expression shape.
1st Expression shape :
2nd Expression Shape :
3rd Expression Shape :
How parallel shape works :
When we drop a file at receive location Orchestration in instantiated and when control reaches the parallel shape, it starts it execution from left to right i.e. the 1st expression shape runs firstly and then rest of them. Even if we insert delay shape after 1st expression shape the 2nd expression shape does not get starts.So therefore parallel shape is not about concurrent execution.
Output in DebugView :