Using views to maintain Petri-net-based process models

A software process model is a complex entity describing activities, products and quality aspects of the "real" software-production process. The ever-changing nature of the software process imposes a continuous control of its evolution; maintenance should adapt the process model to accurately reflect the state of the real process. Presently, process model maintainers have to make evolve these complex models under time pressure and with very little assistance. In this paper we present a preliminary approach for improving maintainability of Petri-net-based process models using the concept of view. A view can be seen as the sub-model capturing the perception a participant has about the process. We show how views can structure a model as a set of more abstract modules which are easy to make evolve. After evolution, views can be composed using a set of formally defined operators to obtain a new process model in an automatic way. Our study is applied to the Process Weaver modelling language. After a short presentation of the Process Weaver formalism, we illustrate view definition with an example of a review process model. View evolution and view composition are also introduced through a scenario of process model change based on the above example.