Component library retrieval using property models

Abstract

The re-use of products such as code, specifications, design decisions and documentation has been proposed as a method for increasing software productivity and reliability. A major problem that has still to be adequately solved is the storage and retrieval of re-usable 'components'. Current methods, such as keyword retrieval and catalogues, rely on the use of names to describe components or categories. This is inadequate for all but a few well established components and categories; in the majority of cases names do not convey sufficient information on which to base a decision to retrieve. One approach to this problem is to describe components using a formal specification. However this is impractical for two reasons; firstly, the limitations of theorem proving would severely restrict the complexity of components that could be retrieved and secondly the retrieval mechanism would need to have a method of retrieving components with 'similar' specifications. This thesis proposes the use of formal 'property' models to represent the key functionality of components. Retrieval of components can then take place on the basis of a property model produced by the library's users. These models only describe the key properties of a component, thereby making the task of comparing properties feasible. Views are introduced as a method of relating similar, non identical property models, and the use of these views facilitates the re-use of components with similar properties. The language Miramod has been developed for the purpose of describing components, and a Miramod compiler and property prover which allow Miramod models to be compared for similarity, have been designed and implemented. These tools have indicated that model based component library retrieval is feasible at relatively low levels of the programming process, and future work is suggested to extend the method to encompass earlier stages in the development of large systems.