During the development of a large software system, the dependencies between the tasks of developers beget the needs of communication and coordination among developers. As an analytical instrument to manage and control the cost of communication and coordination in software development, this paper introduces the concept of
to measure the task dependencies between developers. In particular, to deal with the greatly increased cost of communication and coordination in offshore and outsourcing development due to barriers of stretched distances and cultural differences, this paper further introduces the concept of
to measure the task dependencies between geographically distributed development sites. Methods of computing developer coupling and site coupling are illustrated with examples, and their potential usages for controlling and managing communication and coordination in global software development are described.