Remembering the Future

claiming that BPEL is perfect and complete would be foolish. I think that a more interesting question is: Can BPEL evolve to address some of the existing missing features or is there something flawed in the BPEL interaction, scoping, control flow and exception/eventing model that would prevent it in the future to fill the existing gaps? The work that Collaxa has done in the user task management area is one evidence that user tasks and portal integration can very easily be added to BPEL. More specifically it showcases the composability of the web services/SOA approach compared to the monolith approach showcased by more traditional workflow languages. On the support for unstructured flow, the BPEL eventHandler and the BPEL pick activity actually represent a great step forward, so I think that this shortcoming is more a lack of knowlege around BPEL than a real limitation.

So, by second-class citizen I mean a situation when people cannot directly influence a process. In other words, a process designer assumes some humans involvement in certain steps of the process. E.g. I'm supposed to process purchase orders, so the designer defines POService that participates in the process and this service somehow involves me (via some sort of UI). The same applies for Task Manager. These predefined 'entry points' are ok in most cases. However, it is difficult to perform what I call improvisation – something gets wrong so that automated participants do not know what to do. If these participants are not flexible enough (i.e. they don't have sufficient support for humans), the process ends up in some failure state.