A case study of evolution in object oriented and heterogeneous architectures

In order to properly understand a technology, it is important to know not only its strengths but also its limits. In this paper, we investigate the limits of object oriented technology. We present a case study in which we compare two di€erent architectures for the same program ± a student registration system which belongs to the domain of reactive repositories. We started our case study with a model produced by Object Modeling Technique (OMT), and used it for two di€erent implementations: a homogeneous one (HOA) and a heterogeneous one (HTA). The HOA results in an object oriented system consisting of classes and their dependencies, while the HTA combines traditional imperative programming with a relational database. We evaluated the evolvability of both resulting programs by adding new use cases. HTA proved to be easier to evolve than HOA. In the paper, we discuss possible reasons for this ®nding. Ó 1998 Elsevier Science Inc. All rights reserved.