Experience with Fagan's inspection method

Abstract Fagan's inspection method was used by a software development group to validate requirements specifications for software functions. The experiences of that group are described in this paper. In general, they have proved to be favourable. Because the costs of fixing errors in software were known, the payback for every hour invested in inspection was shown to be a factor 30. There are also other benefits that are much more difficult to quantify directly but whose effect is significant in terms of the overall quality of the software. Some pointers are given at the end of this paper for those who want to introduce Fagan's inspection method into their own development environment.