Formal Representations of the Data Flow Diagram: A Survey

Structured analysis and design methodology has now been replaced by object oriented analysis and design software development techniques. A major design artifact in structured approach is the data flow diagram (DFD). DFD is very important for the modernization of old legacy systems. It is also very useful in requirement elicitation. However, DFD lacks formalism and by representing DFD formally, ambiguity and inconsistencies can be removed. Formal representation of DFD and its formal semantics help in better understanding of requirements and design. In this paper, we present a survey of techniques that formally represent or give formal semantics to the data flow diagram. We analyze formal representation techniques using analysis parameters. On the basis of identified parameters, we present an analysis table, which describes the strengths and weaknesses of representation techniques.