Formal specification and representation of design patterns using RTPA

Software patterns are recognized as an ideal documentation of expert knowledge in software design and development. However, its formal model and rigorous semantics have never been generalized and matured. The traditional UML specification and some formal specification attempts cannot capture the essence of generic patterns precisely, understandably, and essentially. A generic model of patterns is presented in this paper using Real-Time Process Algebra (RTPA). The formal model of patterns are more readable and highly generic, which can be used as the meta model to denote any design patterns deductively, and can be translated into code in programming languages by supporting tools. This work reveals that a pattern is a highly complicated and dynamic structure of software design encapsulation, because of its complex and flexible internal associations between multiple abstract classes and instantiations. The generic model of patterns is not only applicable to existing patterns' description and comprehension, but also useful for future patterns' identification and formalization.