Journal of Computer and Software Engineering, Vol. 3, No.4 (1995), pp. 427-459

A Comparative Analysis of Entity-Relationship Diagrams1

Il-Yeol Song Drexel University Mary Evans USConnect E.K. Park U.S. Naval Academy

The purpose of this article is to collect widely used entity-relationship diagram (ERD) notations and so their features can be easily compared, understood, and converted from one notation to another. We collected ten different ERD notations from text books and CASE tools. Each notation is depicted using a common problem and includes a discussion of each characteristic and notation. According to our investigation, we have found that ERD features and notations are different in seven features: whether they allow n-ary relationships, whether they allow attributes in a relationship, how they represent cardinality and participation constraints, the place where they specify constraints, whether they depict overlapping and disjoint subclass entity-types, whether they show total/partial specialization, and whether they model the foreign key at the ERD level. We conclude that many of the ER diagrams we studied are different in how they depict the criteria listed above. In order to convert one diagram to another, some notations must be extended and carefully converted from one notation into another. We also discuss the limitations of existing CASE tools in terms of modeling capabilities and supporting diagrams. Keywords: Entity-Relationship Diagrams, ERD, design, modeling, CASE

1Correspondence

should be addressed to Il-Yeol Song, College of Information Science and Technology, Drexel University, 32nd and Chestnut Streets, Philadelphia, PA 19104. Email: songiy@post.drexel.edu

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Journal of Computer and Software Engineering, Vol. 3, No.4 (1995), pp. 427-459

1 INTRODUCTION
The purpose of this article is to collect widely used entity-relationship