A CASE tool for information system project and development

Presents a project to develop a tool to support the design of information systems and the development of the first prototype, which can define the dynamic parts of information systems. The purpose is to develop a CASE tool that can be used even by semi-inexperienced users (i.e. users without particular knowledge of the logical and physical structuring of an IS). The Information System Design Support system (ISYDES) has two main parts: one allows the definition of the static structure of data through a simple conceptual model which can be directly translated into a relational one (to this end, an object-oriented generalization of an entity-relationship diagram is proposed), whereas the other allows the definition of functions, which constitute the dynamic part of an IS, through a simple graphical formalism (based on UML activity diagrams). Attention is focused on the second part of the tool. The formalism adopted is described in detail, and the procedure that transforms the formalism into a labelled and controlled Petri net is presented. All the dynamics of an IS are provided for by Petri nets as they can be embedded into the relational database management system through their representation in terms of relations