Constructional design patterns as reusable components

Reusing software is a challenge to researchers and practitioners. Design reuse, in the form of object-oriented design patterns, has emerged with the premise that coding is not the most difficult part of building software, it is the decisions we make early at the design level. Design patterns promise new reuse benefits early in the development lifecycle. To reap the benefits of deploying these proven design solutions, we need to define design composition techniques to construct applications using patterns. These techniques should be supported by versatile design models. In this paper, we introduce a new composition approach that utilizes constructional design patterns as building blocks. The term constructional is used for a particular type of patterns that abstract a structure of interfacing classes. The approach glues together the design structure of patterns at various levels of abstraction for the purpose of developing pattern-oriented designs. The internal details of the pattern structure are hidden at hi gh design levels (pattern views) and are traceable to lower design levels (class views). We define pattern interfaces and develop three hierarchical traceable views: namely the Pattern-Level, Pattern-Level with Interfaces, and Detailed Pattern-Level views. Each design view represents a particular design level granularity with different types of relationships between design artifacts. The proposed pattern views represent a visual method to capture interaction between patterns while hiding details not utilized directly in the design. We use an example to illustrate the applicability of the approach.