IDEF
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The family of ICAM Definition Languages, short IDEF, were initiated in the 1970s and finished being developed in the 1980s. These "definition languages" have become standard modelling techniques. They cover a range of uses from function modelling to information, simulation, object-oriented analysis and design and knowledge acquisition. Specifically, IDEF0 is a functional modelling language building on SADT, and IDEF1X addresses information models. IDEF1X was created by the U.S. Air Force based on ERDs.
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Reference
- IEEE Std 1320.1-1998. IEEE Standard for Functional Modeling Language—Syntax and Semantics for IDEF0. New York: IEEE, 1998.
- IEEE Std 1320.2-1998. IEEE Standard for Conceptual Modeling Language Syntax and Semantics for IDEF1X. New York: IEEE, 1998.
History
IDEF is short for ICAM DEFinition language. ICAM was an initiative managed by the US Air Force out of Wright Patterson AFB, Materials Laboratory and was part of their Technology Modernization efforts, specifically the Computers in Manufacturing (CIM) initiative. ICAM is short for Integrated Computer-Aided Manufacturing.
The specific projects that produced IDEF were the IISS projects (project priorities 6201, 6202 and 6203). IISS stands for "Integrated Information Support System" and was an effort to create an information processing environment that could be run in heterogeneous physical computing environments. The intent was to create 'generic subsystems' which could be used by a large number of companies (contractors to the Air Force, and other armed forces).
There were various, exclusive, and different methods for storing computer data Sequential (VSAM), Hierarchical (IMS), Network such as Cincoms TOTAL and CODASYL databases (such as Culinet's IDMS). Relational had not, yet, become accepted in the general IT community as DB2 had not been released by IBM.
The ICAM project office deemed it valuable to create a "neutral" way of describing implemented physical data structures so that a way could be found to process data independently of the way it was physically stored. Thus the IDEF1 language was created to allow a neutral description of existing physical data structures that could be equally applied regardless of the storage method (regardless of the DBMS, or file access method).
IDEF1 was the result of the IISS-6201 project, and was further extended into IDEF1X by the IISS-6202 project.
The sub-contractor making the most contribution to the content of IDEF1 (and IDEF1X) was DACOM, the Dan Appleton Company. Principle contractors included Boeing and McDonnell_Douglas Corporations.
The most beneficial value of the IDEF1 data modeling technique was its ability to represent data structures independent of how they are to be stored. So, even though IDEF1 started its existence as a way to model physical data structures in a neutral way, it quickly became adopted by data modelers and data analysts as a way to represent data structures during requirements gathering sessions. This allowed the decision of which DBMS to use after the nature of the data structures to be implemented was known, with the potential benefit of reducing the "misfit" of data structure requirements to the capabilities, and limitations, of the DBMS.
As IDEF was produced by government funds, the technique is in the public domain. Therefore the earliest CASE tools utilized IDEF1X as its representation technique for data modeling. (If you click on the link for CASE you will see a picture of ERwin, which is showing a data model using the IDEF1X notation.)
The IISS projects actually produced working prototypes of an information processing environment that would run in heterogeneous computing environments. Current advancements in such techniques as Java and ODBC are now achieving the goals of ubiquity and versatility across computing environments that was first demonstrated by IISS.