Significant amount of work has been done in software engineering in terms of reuse. With the use of object-orientation and design patterns that support the development of reusable modules, it appears that the development and reuse of software modules in creating new systems is becoming more and more common. The software engineering world, however has taken reuse more seriously than database; more research and improvement in reuse has been made in software engineering than in database. This paper investigates how software engineering metrics can be applied in the development of reusable database modules. This research provides a model for predicting the reusability of EXPRESS modules. It establishes a relationship between coupling and reusability of EXPRESS modules, and provides a set of metrics that may be used in the proposed model for measuring coupling in EXPRESS modules.