Modeling the Variability of Architectural Patterns

Architectural patterns provide proven solutions to recurring design problems that arise in a system context. A major challenge for modeling patterns in a system design is effectively expressing pattern variability. However, modeling pattern variability in a system design remains a challenging task mainly because of the infinite pattern variants addressed by each architectural pattern. This paper is an attempt to solve this problem by categorizing the solution participants of patterns. More precisely, we identify variable participants that lead to specializations within individual pattern variants and participants that appear over and over again in the solution specified by several patterns. With examples and a case study, we demonstrate the successful applicability of this approach for designing systems. Using the UML extension mechanism, we offer extensible architectural modeling constructs that can be used for modeling several pattern variants.