A Framework for Evolutionary Information Model Development

Abstract

Large scale information modelling projects, like the development of ISO/STEP, require a modelling approach that does not develop a new model from scratch, but rather base it on a more generic model which, in turn, is based on an even more abstract model, etc. The resulting structure shows a layered framework. On top of which can be found the most generic concepts and downward the more specific concepts with increased semantics. The benefits of such a model development approach are improvements in: version management, object orientated modelling, concurrent model development, controlled change, standardized interfaces, conformance testing etc. This paper describes an environment which supports the development of a new model out of one or more generic parent models. The generation process consists of two steps. In the first step entities of the parent models can be instanciated while constraining the inherited behaviour and introducing new behaviour. In fact this process is identical with instanciating run time objects from class templates in the object oriented paradigm. However, in the authors'development environment an important (inherited) property of each entity is self-reproduction. In the second step, therefore, each instance is forced to represent its run time state into some kind of information modelling language specification. Appropriate measures are taken to guarantee that the resulting model will conform the behaviour of its parent model(s). The paper demonstrates this approach in a multi-layered example currently being implemented and explores several implementation issue