Composing architectures based on architectural patterns for problem frames

Abstract. The use of patterns is a promising way of developing high-quality software in a systematic way. Patterns can be used in different phases of the soft-ware lifecycle. Problem frames are patterns for representing simple software de-velopment problems, and architectural patterns are patterns for representing the coarse-grained structure of a piece of software. In a recent paper, we have defined architectural patterns corresponding to Jackson’s problem frames. To make use of problem frames, complex problems have to be decomposed into simple ones. The corresponding architectural patterns then provide solution struc-tures for these simple problems. Now the question arises how to combine the so-lutions structures of the simple subproblems to obtain a solution structure for the complex problem. The present paper addresses this question. Different subproblems of a complex problem can be related in various ways. They can be independent of each other, they can exclude each other, or they may have to be solved in a specific order. Such information can be used to combine the so-lutions structures of the subproblem to a solution structure of the overall problem. In this paper, we present a pattern-based software development process using problem frames and the corresponding architectural patterns. In decomposing a complex problem into simple subproblems, the relationships between the sub-problems are recorded explicitly. Based on this information, we give guidelines how to derive the software architecture for the overall problem from the software architectures of the simple subproblems.