To remain competitive in the fast paced world of software development, managers must optimize the usage of their limited resources to deliver quality products on time and within budget. In this paper, we present an approach (The Top Ten List) which highlights to managers the ten most susceptible subsystems (directories) to have a fault. Managers can focus testing resources to the subsystems suggested by the list. The list is updated dynamically as the development of the system progresses.

We present heuristics to create the Top Ten List and develop techniques to measure the performance of these heuristics. To validate our work, we apply our presented approach to six large open source projects (three operating systems: NetBSD, FreeBSD, OpenBSD; a window manager: KDE; an office productivity suite: KOffice; and a database management system: Postgres). Furthermore, we examine the benefits of increasing the size of the Top Ten list and study its performance.