Conceptual Modelling for Temporal Information Systems

Abstract

Recent years have witnessed a growing realisation that the development of information systems is becoming increasingly more difficult as user requirements become broader and more sophisticated. Most of the errors that are detected in information systems can be traced to the early stages of development. Functional requirements specification formalisms require formality and rigour in order to lead to improved information systems and to describe reality in a way that is close to users' perceptions. At the same time they should include the concepts for achieving such a purpose.To this end, this thesis develops a formalism for specifying requirements for temporal information systems. The formalisms has three interrelated components: a model based on facts for defining the structural components of an application domain and which supports the explicit modelling of time and the definition of calendar systems, an algebra for that model in order to provide the ability for writing expressions about the concepts of the model and a rule language for defining the rules and constraints of the application domain and also the reaction of the information system when certain situation occur.