  An essential characteristic of mature software and system development
organizations is the definition and use of explicit process models. For a
number of reasons, it can be valuable to produce new process models by
tailoring existing process standards (such as the V-Modell XT). Both process
models and standards evolve over time in order to integrate improvements or
adapt the process models to context changes. An important challenge for a
process engineering team is to keep tailored process models aligned over time
with the standards originally used to produce them. This article presents an
approach that supports the alignment of process standards evolving in parallel
to derived process models, using an actual industrial example to illustrate the
problems and potential solutions. We present and discuss the results of a
quantitative analysis done to determine whether a strongly tailored model can
still be aligned with its parent standard and to assess the potential cost of
such an alignment. We close the paper with conclusions and outlook.
