Elementary structures in entity-relationship diagrams: a new metric for effort estimation

The paper describes a systematic treatment of the entity relationship diagram, resulting in the identification of three elementary data structures. Recognition of these structures is shown to constitute a useful analytical and diagnostic tool for data modelling. An algorithm for counting the number of occurrences of each type of structure in a data model is presented and the possibility is explored of using these values as the basis for a metric for system development effort estimation. Such a metric could be applied earlier in the development cycle than others currently in use. For a specific class of system an empirical expression for the estimation of development effort is determined.