SYSTEMS ENGINEERING: A DATA MODEL VIEW

Abstract

ABSTRACTDuring the late 70's the U.S. Air Force sponsored a program called Integrated Computer Aided Manufacturing or ICAM. The term ICAM Definition arose and was abbreviated to IDEF. Three IDEF modeling techniques were developed: IDEFO (process modeling), IDEF1 (data modeling) and IDEF2 (dynamics modeling). IDEF1X is an outgrowth of IDEF1. See Reference 1.This paper presents an IDEF1X data model view of systems engineering. It shows some of the fundamental data elements of Systems Engineering and their logical relationships. The data model is applicable to any product development, from toys to space ships.The model uses two particular data constructs (FUNCTION RELATION, and BEHAVIOR CHARACTERISTIC) that provide the flexibility needed to use the highly structured world of databases to provide a tool for the highly unstructured and creative world of Systems Engineering. The model evolved over the past two years as a result of the author's participation in Martin Marietta's efforts to develop an integrated data base.The lack of a widely accepted view of Systems Engineering data may partly account for the shortage of good Computer Aided Systems Engineering (CASE) tools and/or the lack of user acceptance of some of the CASE tools. The author hopes this paper will help stimulate dialog that will result in one or more widely accepted views upon which CASE tools can proliferate. The paper is organized into 6 topics: Data modeling tutorial A data model view of systems engineering Anatomy of a performance requirement Relation between data models and CASE tool functionality Conclusions Recommendation