Design of software architecture is seen as abstraction over the software domain, and describing architecture is considered to be a modeling process. A general view of a modeling process is presented and illustrated in the context of application domain modeling and of software domain modeling. The implications of this perspective are investigated in order to capture objectives and concrete forms of architectural descriptions.The consequences of this perspective on architecture are characterized.
1: IntroductionIn every software system, some architecture is present. The problem is that architecture is only implicitly available. The architecture did exist for developers during the design phase, but because it was not expressed explicitly, the architecture either has been lost, or has only been reproduced to some extent in software documentation. The consequences of the architecture are present in terms of the properties and qualities of the software.Software Architecture. Software architecture is defined in various different ways.[9]: "Abstractly, software architecture involves the description of elements from which systems are built, interactions among those elements, patterns that guide their composition, and constraints on these patterns. In general, a particular system is defined in terms of a collection of components and interactions among those components. Such a system may in turn be used as a (composite) element in a larger system design." [3]: "A software architecture is a description of the subsystems and components of a software system and the relationships between them. Subsystems and components are typically specified in different views to show the relevant functional and non-functional properties of a software system. The software architecture of a system is an artifact. It is the result of the software design activity." [10]: "An architecture integrates separate but interfering issues of a system, such as provisions for independent evolution and openness combined with overall reliability and performance requirements. An architecture defines guidelines that together help to achieve the overall targets without having to invent ad hoc compromises during system composition." [1]: "The software architecture of a program or computing system is the structure or structures, which comprise software components, the externally visible properties of those components, and the relationships among them." [8]: "Architecture means style or manner of building". For a software system we interpret software architecture to mean the actual choice of architectural abstractions and language mechanisms, especially abstraction mechanisms, and the actual use of the elements chosen, i.e. how they are combined, their iterations, variations etc."In a brief characterization of these definitions of software architecture we claim that these describe organization only, not abstraction. We distinguish between organizing and abstracting: If we organize a certain domain, we only put some kind of order in the domain, among the e...
