Human tasks in business processes allow us to include activities that are carried out by humans. So far, we have seen that in BPEL processes we can invoke external services. We call these automated activities. However, often an activity needs to be included that requires human intervention.

Human interactions in business processes can be very simple, such as approval of certain tasks or decisions, or complex, such as delegation, renewal, escalation, nomination, chained execution, and so on. Human interactions can include data entries, process monitoring and management, process initiation, exception handling, and so on.

One of the simplest and probably the most common human interactions is approval. In our book warehousing business process, which we developed in Chapter 4, Conditions and Loops, a human task might be required to get an approval of the selected bookstore by a business user, instead of letting the process select the appropriate bookstore (Bookstore A...