Editing IDEF (section)

== History ==
IDEF originally stood for [[Integrated Computer-Aided Manufacturing|ICAM]] Definition, initiated in the 1970s at the US Air Force Materials Laboratory, [[Wright-Patterson Air Force Base]] in Ohio by [[Dennis E. Wisnosky]], Dan L. Shunk, and others.<ref name="Sav96">Charles M. Savage (1996). ''Fifth Generation Management: Co-creating Through Virtual Enterprising, Dynamic Teaming, and Knowledge Networking'' Butterworth-Heinemann, 1996. {{ISBN|0-7506-9701-6}}. p. 184.</ref> and completed in the 1980s. IDEF was a product of the ICAM initiative of the [[United States Air Force]]. The [[Institute of Electrical and Electronics Engineers|IEEE]] recast the IDEF abbreviation as Integration Definition."<ref name="IEEE IDEF Ref">IEEE Standard for Functional Modeling Language—Syntax and Semantics for IDEF0, Software Engineering Standards Committee of the IEEE Computer Society, IEEE-SA Standards Board, The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA, [https://web.archive.org/web/20130509181157/http://standards.ieee.org/findstds/standard/1320.1-1998.html IEEE Std 1320.1-1998], 25 June 1998</ref>

The specific projects that produced IDEF were ICAM project priorities 111 and 112 (later renumbered 1102). The subsequent Integrated Information Support System (IISS) project priorities 6201, 6202, and 6203 attempted to create an [[Data processing|information processing]] environment that could be run in [[heterogeneous]] physical computing environments. Further development of IDEF occurred under those projects as a result of the experience gained from applications of the new modeling techniques. The intent of the IISS efforts was to create 'generic subsystems' that could be used by a large number of collaborating enterprises, such as U.S. [[defense contractor]]s and the armed forces of friendly nations.

At the time of the ICAM 1102 effort there were numerous, mostly incompatible, [[data model]] methods for storing computer data &mdash; [[Sequential access|sequential]] ([[VSAM]]), [[Hierarchical model|hierarchical]] ([[Information Management System|IMS]]), [[Network model|network]] ([[Cincom]]'s TOTAL and [[CODASYL]], and [[Cullinet]]'s [[IDMS]]). The [[relational data model]] was just emerging as a promising way of thinking about structuring data for easy, efficient, and accurate access. [[Relational database management system]]s had not yet emerged as a general standard for data management.

The ICAM program office deemed it valuable to create a "neutral" way of describing the data content of large-scale systems. The emerging academic literature suggested that methods were needed to process [[Data independence|data independently]] of the way it was [[data structure|physically stored]]. Thus the IDEF1 language was created to allow a neutral description of data structures that could be applied regardless of the storage method or file access method.

IDEF1 was developed under ICAM program priority 1102 by Robert R. Brown of the [[Hughes Aircraft Company]], under contract to [[SofTech, Inc.]] Brown had previously been responsible for the development of [[Information Management System|IMS]] while working at [[Rockwell International]]. Rockwell chose not to pursue IMS as a marketable product but [[International Business Machines|IBM]], which had served as a support contractor during development, subsequently took over the product and was successful in further developing it for market. Brown credits his Hughes colleague Timothy Ramey as the inventor of IDEF1 as a viable formalism for modeling information structures. The two Hughes researchers built on ideas from and interactions with many luminaries in the field at the time. In particular, IDEF1 draws on the following techniques:
* the evolving natural language information model ([[NIAM|ENALIM]]) technique of [[G. M. Nijssen]] ([[Control Data Corporation]]) — this technique is now more widely known as [[NIAM]] or the object–role model [[object–role modeling|ORM]];
* the network data structures technique, popularly called the [[CODASYL]] approach, of [[Charles Bachman]] ([[Honeywell Information Systems]]);
* the hierarchical data management technique, implemented in IBM's IMS data management system, developed by [[R. R. Brown]] ([[Rockwell International]]);
* the relational approach to data of [[E. F. Codd]] ([[IBM]]);
* The [[entity–relationship model|entity–relationship approach]] (E–R) of [[Peter Chen]] ([[UCLA]]).
The effort to develop IDEF1 resulted in both a new method for information modeling and an example of its use in the form of a "reference information model of manufacturing." This latter artifact was developed by D. S. Coleman of the D. Appleton Company (DACOM) acting as a sub-contractor to Hughes and under the direction of Ramey. Personnel at DACOM became expert at IDEF1 modeling and subsequently produced a training course and accompanying materials for the IDEF1 modeling technique.

Experience with IDEF1 revealed that the translation of information requirements into database designs was more difficult than had originally been anticipated. The most beneficial value of the IDEF1 information modeling technique was its ability to represent data independent of how those data were to be stored and used. It provided data modelers and data analysts with a way to represent data requirements during the requirements-gathering process. This allowed designers to decide which DBMS to use after the nature of the data requirements was understood and thus reduced the "misfit" between data requirements and the capabilities and limitations of the DBMS. The translation of IDEF1 models to database designs, however, proved to be difficult.