Software process validation: Quantitatively measuring the correspondence of a process to a model

To a great extent, the usefulness of a formal model of a software process l ies in its ability to accurately predict the behavior of the executing proc ess. Similarly, the usefulness of an executing process lies largely in its ability to fulfill the requirements embodied in a formal model of the proce ss. When process models and process executions diverge, something significa nt is happening. We have developed techniques for uncovering and measuring the discrepancies between models and executions, which we call process vali dation. Process validation takes a process execution and a process model, a nd measures the level of correspondence between the two. Our metrics are ta ilorable and give process engineers control over determining the severity o f different types of discrepancies. The techniques provide detailed informa tion once a high-level measurement indicates the presence of a problem. We have applied our process validation methods in an industrial case study, of which a portion is described in this article.