| System modelling is an important sub-area of software configuration management (SCM); it is concerned with how software systems are composed from their constituent elements. This dissertation investigates several problems associated with current approaches, and introduces the ConForm framework for visual system modelling.; A shortcoming of most SCM environments is that their system modelling notations incorporate only a small amount of the available information about a system and its components; in particular, architectural information, such as system structure and component interconnections, is rarely considered. There are several resulting problems: (1) System models are often inscrutable and difficult to derive by visual inspection. (2) Usually, there is no guarantee that the components listed in a system model can be combined in a meaningful way, or that all components are present. (3) It is often difficult to reason about the effects of replacing components, and only limited automated support may be given for the construction of new systems. (4) System modelling notations are often inherently textual, ad hoc, lack formal foundations, and are tied to a particular programming language.; The purpose of ConForm (Configuration Formalism) is to address these inadequacies within a single framework. In particular, ConForm: (1) supports the modelling of software systems as a composition of versioned components; (2) explicitly models architectural information, such as system structure and component interconnections; (3) models relationships between versions of components based on architectural information; (4) has a core formal model that is independent of any implementation language or platform, but may be extended to handle industrial languages such as C; (5) allows user-defined design constraints to be modelled and enforced; and (6) has both a textual and a visual representation.; ConForm's data model and calculus of system construction are formally defined using the Z specification language. A prototype version of ConForm has been constructed as a proof of concept, using the formal definition as a guide. |
