The Added Value of Programmed Graph Transformations – A Case Study from Software Configuration Management

Abstract

Model-driven software engineering intends to increase the productivity of software engineers by replacing conventional programming with the development of executable models at a high level of abstraction. It is claimed that graph transformation rules contribute towards this goal since they provide a declarative, usually graphical specification of complex model transformations. Frequently, graph transformation rules are organized into even more complex model transformations with the help of control structures, resulting in full-fledged support for executable behavioral models. This paper examines the added value of programmed graph transformations with the help of a case study from software configuration management. To this end, a large model is analyzed which was developed in the MOD2-SCM project over a period of several years. The model was developed in Fujaba, which provides story diagrams for programming with graph transformations. Our analysis shows that the model exhibits a strongly procedural flavor. Graph transformation rules are heavily used, but typically consist of very small patterns. Furthermore, story diagrams provide fairly low level control structures. Altogether, these findings challenge the claim that programming with graph transformations is performed at a significantly higher level of abstraction than conventional programming.