Alternative Models for Structural Design Patterns

To give a consistent and more valuable feature on models, we propose that model-driven processes should be able to reuse the expert knowledge generally expressed in terms of patterns. We focus our study on a detailed design review activity, which precedes a coding stage in an object-oriented language. We make the hypothesis that design models lack in good object design practices. As we do not find any model inspection tool that urges the use of patterns in the most automatic possible way, we present here the concept of an “alternative model” and its usage within our design review. An “alternative model” is a model which solves the same problem as the pattern, but with a more complex or different structure than the pattern. Each pattern has many “alternative models”. Structural characterization permits us to detect model fragments substitutable with a pattern. Criteria of object-oriented architecture and software engineering quality permit us to construct a knowledge base dedicated to design practices and to explain why the substitution makes the design more attractive.