A catalog of architectural primitives for modeling architectural patterns

Abstract

Architectural patterns are a fundamental aspect of the architecting process and subsequently the architectural documentation. Unfortunately, there is only poor support for modeling architectural patterns for two reasons. First, patterns describe recurring design solutions and hence do not directly match the elements in modeling languages. Second, they support an inherent variability in the solution space that is hard to model using a single modeling solution. This paper proposes to address this problem by finding and representing architectural primitives MotivationThe software architecture of a system needs to be rigorously documented in order to profit from the advantages of architecture-centric development and evolution. One of the most significant aspects of documenting software architectures is the representation of architectural patterns (also known as architectural styles 1 ). In general, a pattern is a problem-solution pair in a given context. A pattern does not only document 'how' a solution solves a problem but also 'why' it is solved, i.e., the rationale behind this particular solution. Architectural patterns help to document architectural design decisions, facilitate communication between stakeholders through a common vocabulary, and assist in analyzing 1 In this paper we do not distinguish between the terms 'architectural pattern' (used e.g. in [6, 39, 44]) and 'architectural style' (used e.g. in [42]). For the sake of simplicity, we shall use only the term 'architectural pattern' for the rest of this paper. Their commonalities and differences are elaborated in [2]. 1 the quality attributes of a software system. There are three major approaches, that have been used so far for modeling architectural patterns:1. Architecture Description Languages (ADLs), which aim at representing software architectures in general [27]; 2. the Unified Modeling Language which is a generic modeling language but can also be used to describe software architectures [37,26,4]; 3. some formal or semi-formal approaches for the formalization of pattern specifications [8,29,43,25].Unfortunately, none of these approaches succeeds in effectively modeling architectural patterns for the following reasons:• The approaches are too limited in the abstractions they propose to grasp the rich concepts found in patterns.UML, to start with, falls short in offering certain standard concepts of architectural patterns [1,26,20] • The approaches do not deal with the inherent variability of architectural patterns. This is not restricted to architectural patterns but it is a general problem of specifying patterns because each pattern covers not only one (parametric) solution, but informally describes a whole solution space for a recurring design problem. It is obvious in UML and ADLs, and even more so in the third aforementioned approach that deals with the formal specification of design patterns [8,29,43,25]: such methods are capable of specifying one particular solution in the solution space of the pattern, but fail to specify the who...

A survey of existing approaches for pattern search and selection

“…Related, but very different problems of selecting architectural primitives [Zdun and Avgeriou 2008] and selecting pattern sequences have not been considered. Those are possible directions for future research.…”

Configuration logics: Modeling architecture styles

“…ACME [31], Darwin [32]), and with approaches that use OCL [6] (e.g. [33,34], where OCL is used to extend UML [35]) to intentionally define architecture styles. Our approach achieves a strong semantic integration between architectures and architecture styles.…”

Using Model Transformation Techniques for the Superimposition of Architectural Styles

“…Most of the work has been oriented towards the description of new architectural styles. Some work has focused on the classification of architectural styles, and other proposals have tried to define primitives to describe and/or compose architectural styles [9] [19]. But, as far as we know, no proposals have paid attention to their automatic superimposition.…”