EVENT-EXTENDED ENTITY-RELATIONSHIP DIAGRAMS FOR UNDERSTANDING SIMULATION MODEL STRUCTURE AND FUNCTION

Because of the similarities in the underlying modeling constructs of database design and simulation modeling proven effective database design methods, if enhanced, can be adapted to simulation modeling. This paper presents the Event-Extended Entity-relationship Diagram that enables simulation model designers and users to better communicate among themselves concerning the entities, attributes, relationships, and events that exist within simulation models. This modeling method is an extension of the highly successful database modeling tool called the Entity-relationship (E-R) diagram, developed by Chen (1976) and clearly discussed by Grant (1987). The E-R diagram expresses the logical associations among data. This paper demonstrates the need for such a communication method for designers and users, It briefly introduces some of the concepts in E-R modeling and shows the similarity of model constricts between simulation models and database models as the basis for beginning with the E-R diagram, It then sets down the semantic constructs required to enhance E-R diagrams to fore Event-Extended Entity-relationship diagrams. The paper illustrates The new constructs with an example and with discussion of its communication potential. The paper points cit the relationship between the Event-Extended Entity- relationship diagram and the design of either file structures or database structures needed to support a simulation model, Lastly, it sketches oat the design steps leading to the development of simulation modeling computer code