The kiss of death for a software metrics initiative is to use the data for input into an individual’s performance evaluation. Using metrics data for either reward or punishment, such as rank ordering programmers based on their lines of code generated per day, is totally inappropriate. When someone knows the numbers he reports might be held against him, he’ll either stop reporting data at all or only report results that make him look good. Fear of the consequences of reporting honest data is a root cause of many metrics program failures.

Management must make it clear that the purpose of the metrics program is to understand how software is being built, to facilitate making informed decisions, and to assess the impact of process changes on the software work. The purpose is NOT to evaluate individual team members. Control the scope of visibility of different kinds of data, as described in Chapter 12 (Grady 1992). However, it is appropriate to consider the activity of collecting and reporting accurate and timely data in an individual’s performance evaluation. The best results come about when individuals use their private metrics data to judge and correct themselves, thereby improving their personal software process.