RPE and XDW

IHE's ITI and QRPH committees today met again to discuss the similarities and differences between RPE and XDW. I'll start first by giving a quick overview of what each profile is and then discuss my viewpoints on the comparison.

RPE - Retrieve Process for Execution
RPE was a profile that was written a few years ago and at the time was called Retrieve Protocol for Execution where protocol referred to research protocols. The purpose originally was for a protocol executor to retrieve a protocol from the protocol definition manager and execute it while providing updates to a state manager. RPE has evolved since then. Now, The process executor and the process state manager both retrieve the process from the process definition manager and the executor then retrieves executable steps from the process state manager and executes them, finally providing updates to the state manager.

XDW - Cross-enterprise Document Workflow
XDW is a profile where the the XDW content updater consumes a workflow document, performs some workflow steps and replaces the document with an updated workflow document.

When comparing these two profiles, it is very easy to make arguments for both the similarities as well as the differences between them. Some are highlighted below:
Similarities:
Both profiles deal with some type of process or workflow.
Both profiles allow for shared execution of a process or workflow.
Differences:
RPE has more of a central execution architecture while XDW has more of a distributed execution architecture.
RPE attempts to automate the execution steps with executable tasks while XDW does not.
XDW documents the workflow steps that were completed in a document architecture while RPE does not.

Once again, I will argue that several other similarities and differences can easily be documented. So, what is the purpose of having these two separate profiles.

When posed with a problem that could be potentially solved by either of these profiles (or a combination of both), how does one figure out what the best solution is. This is somewhat of an architectural question and some level or art comes into play. However, both ITI and QRPH have agreed to create a decision tree that will help answer this question based on collecting more information about the problem. I will refrain from posting further thoughts till we have some semblance of a finished product from the two committees.