The relationship of performance models to data

Abstract

Performance engineering of software could benefit from a closer integration of the use of performance models, and the use of measured data. Models can contribute to early warning of problems, exploration of solutions, and scalability evaluation, and when they are fitted to data they can summarize the data as a special powerful form of fitted function. Present industrial practice virtually ignores models, because of the effort to create them, and concern about how well they fit the system when it is implemented. The first concern is being met by automated generation from software specifications. The second concern can be met by fitting the models to data as it becomes available. This will adapt the model to the new situation and validate it, in a single step. The present paper summarizes the fitting process, using standard tools of nonlinear regression analysis, and shows it in action on examples of queueing and extended queueing models. The examples are a background for a discussion about the relationship between the models, and measurement data. © 2008 Springer-Verlag Berlin Heidelberg.