Tutorial: enabling flexibility in process-aware information systems #BPM2009

Manfred Reichert of Ulm University and Barbara Weber of University of Innsbruck presented a tutorial on the challenges, paradigms and technologies involved in enabling flexibility in process-aware information systems (PAIS). Process flexibility is important, but you have to consider both build time flexibility (how to quickly implement and configure new processes) and run time flexibility (how to deal with uncertainty and exceptional cases during execution), as well as their impact on process optimization.

We started by looking at the flexibility issues inherent in the imperative approach to BPM, where pre-defined process models are deployed and executed, and the execution logs monitored (in other words, the way that almost all BPMS work today). As John Hoogland discussed this morning, there are a number of flexibility issues at build time due to regional process variations or the lack of a sufficient information about decisions to build them into the process model. There’s also flexibility issues in the run time, mostly around exception handling and the need for ad hoc changes to the process. As all this rolls back in to the process analyst through the execution monitoring, it can be used to optimize the process model, which requires flexibility in evolving the process model and impacting work in progress. The key problem is that there are way too many variants in most real-life processes to realistically model all of them: there needs to be a way to model a standard process, then allow user-driven configuration (either explicitly or based on the instance parameters) at run time. The Provop approach presented in the tutorial allows for selective enabling and disabling of process steps in a master model based on the instance conditions, with a lot of the research based on the interaction between the parameters and the soundness of the resultant models.

Late binding and late modeling approaches use a pre-specified business process with one or more placeholder activities, then the placeholder activities are replaced with a process fragment at run time either from a pre-determined set of process fragments or a process fragment assembled by the user from existing activity templates (the latter is called the “pockets of flexibility” approach, a name that I find particularly descriptive).

Up to this point, the focus has been on changes to the process model to handle variability that are part of normal business, but possibly not considered exceptions. Next, we looked at runtime exception handling, such as the failure or unavailability of a web service that causes the normal process to halt. Exceptions that are expected (anticipated) can be handled with compensation, with the compensation events and handler built into the process model; unexpected exceptions may be managed with ad hoc process changes to that executing instance. Ad hoc process changes can be a bit tricky: they need to be done at a high level of abstraction in order to make it understandable to the user making the change, yet the correctness of the changes must be validated before continuing. This ability needs to be constrained to a subset of the users, and the users who can make the changes may require some assistance to do this correctly.

This was a good tutorial, but I wanted to catch the process mining session so skipped out at the break and missed the last half.

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