Abstract

A lot of effort has been conducted by experienced designers to document good quality practices in software designs in terms of design patterns. However, little emphasis has been placed on patterns usage, which is a basic benefit when claiming reusability of the documented design patterns catalogues. This paper presents a new approach for constructing object oriented design frameworks based only on design patterns as building blocks. The developed frameworks are named Pattern-Oriented Frameworks. The construction of pattern oriented frameworks is illustrated throughout the paper using an example for a common engineering application: Closed-Loop Control systems. These systems are commonly described in terms of block diagrams. The feedback framework is presented as a generic architecture based on design patterns. A pattern diagram is defined to express the framework's architecture in terms of subsystems, design patterns, and associations. A development process is proposed which expresses the framework in two design levels: a pattern diagram and a class diagram. Two approaches for the framework instantiation are illustrated and an instantiation of the framework in a practical application is pointed out to show the benefits of the pattern oriented frameworks approach.