In this paper, we describe the design of a reusable IR framework, called FIRE, that is being implemented to facilitate the development of IR systems. In addition, FIRE is designed to support the experimental evaluation of both indexing and retrieval techniques. First, we discuss the development of reusable software in the IR domain and derive essential criteria for the design of an IR framework. Next, we sketch the object model developed for FIRE. We present the basic concepts and their modeling and show how the components interact when performing indexing and retrieval tasks.