Modeling Variability in Software Process Models

Software process lines (SPrL) are families of highly related processes that are built from a set of core process assets. Software companies can use SPrLs to address the development of different types of projects – development or maintenance, large or small, complex or simple – and therefore reuse process knowledge in an organized way. This can be achieved by either defining a series of processes, one for each context, or by tailoring a general process to each context. Both approaches have their disadvantages, and currently, there are no conclusive proposals about how to manage process variability. In this paper, we propose a combination of notations and tools for formalizing software process models including their variability, which enables automated SPrL tailoring. We use the Eclipse Process Framework Composer for specifying the general process itself, and SPLOT, a feature modeling tool, for specifying process variability. We then use the Modisco/AMW tool to establish constraints between both models, in order to ensure that only reasonable variability is specified. Using an industrial case study, we show how these tools are used to specify and analyze software process models that include variability.