Adapting Function Points to Object-Oriented Information Systems

The object oriented paradigm has become widely used to develop large information systems. This paper presents a method for estimating the size and eeort of developing object oriented software. The approach is analogous to function points, and it is based on counting rules that pick up the elements in a static object model and combine them in order to produce a composite measure. Rules are proposed for counting \Object Oriented Function Points" from an object model, and several questions are identiied for empirical research. A key aspect of this method is its exibility. An organization can experiment with diierent counting policies, to nd the most accurate predictors of size, eeort, etc. in its environment. \Object Oriented Function Points" counting has been implemented in a Java tool, and results on size estimation obtained from a pilot project with an industrial partner are encouraging.