Approximating Change Sets at Philips Healthcare

A single development task such as solving a bug or implementing a new feature often involves changing a number of entities, also known together as a change set. Change sets can be approximated from the version control system. They are then used by the architects and developers to take important decisions. So change sets need to be approximated carefully. It is common to assume that two entities checked-in less than a small time interval from each other, and having the same meta-data associated with them, belong to the same transaction. Transactions may be good approximations of change sets if developers commit change sets in one go and if the required meta-data is available. This is however not the case in the industrial environment (Philips Healthcare) we study. This chapter presents a case study in which we investigated how change sets can be approximated in an environment with a complex workflow and limited meta-data in the version repositories. By doing so, we execute Step 1 and Step 2 of the process described in Section 1.7 to help the software architect. We found that, dependent on the commit practices used, a suitable time intervals between check-in timestamps of files has to be determined and leveraged to reliably approximate change sets.