Meaning of dataflow diagram and entity life history-a systems theoretic foundation for information systems analysis. II

For part I see ibid., p.1-10. Dataflow diagrams and entity life histories are widely-used tools in information systems methodologies. The tools are far more effective than natural language, though their meanings have not yet been clarified. This paper shows how the model developed in part I enables formal characterization of information systems methodologies. That is, it elaborates the meaning of DFDs and ELHs by providing a concrete example throughout. The characterization of DFDs establishes an explicit correspondence between the static structure of a business transaction system and a DFD. This correspondence illustrates the necessary components in designing the file structure of a business system. The ELH of a business system is described as the set of sequences of the system's transactions. Black hole and franchise business systems can be characterized by sequences, while the ELH of a general business system partially defines its dynamic structure.