IDEF

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IDEF Methods: Part of the Systems Engineer’s Toolbox[1]

IDEF (Integration DEFinition) is a family of modeling languages in the field of systems and software engineering. They cover a range of uses from function modeling to information, simulation, object-oriented analysis and design and knowledge acquisition. These "definition languages" have become standard modeling techniques.

Specifically, the initial (and most-widely recognized) languages are IDEF0, which is a functional modeling language building on SADT, and IDEF1, which addresses information models; an adaptation of IDEF1, called IDEF1X, was subsequently created to address database design issues. The IDEF languages were developed under funding from U.S. Air Force and, as such, are in the public domain.

Contents

[edit] History

IDEF originally stands for ICAM Definition, that were initiated in the 1970s at the US Air Force Materials Laboratory, Wright-Patterson Air Force Base in Ohio by Dennis E. Wisnosky and Dan L. Shunk and others.[2] and finished being developed in the 1980s. IDEF was a product of the Integrated Computer-Aided Manufacturing (ICAM) initiative of the United States Air Force. "IDEF" initially stood for "ICAM DEFinition" language; the IEEE standards recast IDEF as "Integration DEFinition."

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

[edit] Functional modeling

Example of an IDEF0 diagram: A function model of the process of "Maintain Reparable Spares".

The IDEF0 Functional Modeling method is designed to model the decisions, actions, and activities of an organization or system.[3] It was derived from the established graphic modeling language Structured Analysis and Design Technique (SADT) developed by Douglas T. Ross and SofTech, Inc.. In its original form, IDEF0 includes both a definition of a graphical modeling language (syntax and semantics) and a description of a comprehensive methodology for developing models.[4] The US Air Force commissioned the SADT developers to develop a function model method for analyzing and communicating the functional perspective of a system. IDEF0 should assist in organizing system analysis and promote effective communication between the analyst and the customer through simplified graphical devices.[3]

[edit] Information modeling

At the time of the ICAM 1102 effort there were numerous, mostly incompatible, data model methods for storing computer data — Sequential (VSAM), Hierarchical (IMS), 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 Systems 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 independently of the way it was physically stored. Thus the IDEF1 language was created to allow a neutral description of data structures, that could be equally applied regardless of the storage method or file access method.

IDEF1 was developed under ICAM program priority 1102 by Dr. Robert R. Brown of the Hughes Aircraft Company, under contract to SofTech, Inc. Dr. Brown had previously been responsible for the development of IMS while working at Rockwell International (Rockwell chose not to pursue IMS as a marketable product; 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.) Dr. Brown credits his Hughes colleague Mr. 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 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 Mr. Ramey. Personnel at DACOM became quite 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 be 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 face the decision of which DBMS to use under various circumstances after the nature of the data requirements was understood. The result was reduction of the "misfit" of data requirements to the capabilities, and limitations, of the DBMS. The translation from IDEF1 models to database designs proved to be difficult, however.

[edit] IDEF1X

Example of an IDEF1X Diagram.

To satisfy the data modeling enhancement requirements that were identified in the IISS-6202 project, a sub-contractor, DACOM, obtained a license to the Logical Database Design Technique (LDDT) and its supporting software (ADAM). LDDT had been developed in 1982 by Robert G. Brown of The Database Design Group entirely outside the IDEF program and with no knowledge of IDEF1. LDDT combined elements of the relational data model, the E-R model, and generalization in a way specifically intended to support data modeling and the transformation of the data models into database designs. The graphic syntax of LDDT differed from that of IDEF1 and, more importantly, LDDT contained interrelated modeling concepts not present in IDEF1. Mary E. Loomis wrote a concise summary of the syntax and semantics of a substantial subset of LDDT, using terminology compatible with IDEF1 wherever possible. DACOM labeled the result IDEF1X and supplied it to the ICAM program.[5][6]

Because the IDEF program was funded by the government, the techniques are in the public domain. In addition to the ADAM software, sold by DACOM under the name Leverage, a number of CASE tools, such as ERwin, use IDEF1X as their representation technique for data modeling.

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 JDBC are now achieving the goals of ubiquity and versatility across computing environments which was first demonstrated by IISS.

[edit] IDEF2 and IDEF3

Example of an Enhanced Transition Schematic, modelled with IDEF3.

The third IDEF (IDEF2) was originally intended as a user interface modeling method. However, since the Integrated Computer-Aided Manufacturing (ICAM) Program needed a simulation modeling tool, the resulting IDEF2 was a method for representing the time varying behavior of resources in a manufacturing system, providing a framework for specification of math model based simulations. It was the intent of the methodology program within ICAM to rectify this situation but limitation of funding did not allow this to happen. As a result, the lack of a method which would support the structuring of descriptions of the user view of a system has been a major shortcoming of the IDEF system. The basic problem from a methodology point of view is the need to distinguish between a description of what a system (existing or proposed) is supposed to do and a representative simulation model that will predict what a system will do. The latter was the focus of IDEF2, the former is the focus of IDEF3.[7]

[edit] IDEF 4

Example of the IDEF4: An Behavior Diagram for methods Implementing Louder.

The development of IDEF4 came from the recognition that the modularity, maintainability and code reusability that results from the object oriented programming paradigm can be realized in traditional data processing applications. The proven ability of the object oriented programming paradigm to support data level integration in large complex distributed systems is also a major factor in the widespread interest in this technology from the traditional data processing community.[7]

IDEF4 was developed as a design tool for software designers who use object-oriented languages such as the Common LISP Object System, Flavors, C++, SmallTalk, Objective C and others. Since effective usage of the object-oriented paradigm requires a different thought process than used with conventional procedural or database languages, standard methodologies such as structure charts, data flow diagrams, and traditional data design models (hierarchical, relational, and network) are not sufficient. IDEF4 seeks to provide the necessary facilities to support the object-oriented design decision making process.[7]

[edit] IDEF5

Example of an IDEF5 Composition Schematic for a Ballpoint Pen.

IDEF5 or Integrated Definition for Ontology Description Capture Method is a software engineering method to develop and maintain usable, accurate, domain ontologies.[8] In the field of computer science ontologies are used to capture the concept and objects in a specific domain, along with associated relationships and meanings. In addition, ontology capture helps coordinate projects by standardizing terminology and creates opportunities for information reuse. The lDEF5 Ontology Capture Method has been developed to reliably construct ontologies in a way that closely reflects human understanding of the specific domain.[8]

In the IDEF5 method, an ontology is constructed by capturing the content of certain assertions about real-world objects, their properties, and their interrelationships and representing that content in an intuitive and natural form. The IDEF5 method has three main components: A graphical language to support conceptual ontology analysis, a structured text language for detailed ontology characterization, and a systematic procedure that provides guidelines for effective ontology capture.[3]

[edit] IDEF Methods

Eventually the IDEF methods have been defined up to IDEF14:

  • IDEF0 : Function modeling[9]
  • IDEF1 : Information Modeling [10]
  • IDEF1X : Data Modeling [11]
  • IDEF2 : Simulation Model Design
  • IDEF3 : Process Description Capture [12]
  • IDEF4 : Object-Oriented Design [13]
  • IDEF5 : Ontology Description Capture [14]
  • IDEF6 : Design Rationale Capture [15]
  • IDEF7 : Information System Auditing
  • IDEF8 : User Interface Modeling
  • IDEF9 : Scenario-Driven IS Design
  • IDEF10 : Implementation Architecture Modeling
  • IDEF11 : Information Artifact Modeling
  • IDEF12 : Organization Modeling
  • IDEF13 : Three Schema Mapping Design
  • IDEF14 : Network Design

In 1995 only the IDEF0, IDEF1X, IDEF2, IDEF3 and IDEF4 had been developed in full.[16] Some of the other IDEF concepts had some prelimary design. Some of the last efforts were new IDEF developments in 1995 toward establishing reliable methods for business constraint discovery IDEF9, design rationale capture IDEF6, humansystem interaction design IDEF8, and network design IDEF14.[1]

In 2009 the methods IDEF7, IDEF10, IDEF11, IDEF 12 and IDEF13 haven't been developed any further then their initial definition.[17]

[edit] See also

[edit] References

This article incorporates text from a publication of the National Institute of Standards and Technology, which, as a U.S. government publication, is in the public domain. Source: [1].

  1. ^ a b Richard J. Mayer (1995) et al. Information Integration for Concurrent Engineering (IICE) Compendium of methods report. Wright-Patterson Air Force Base, Ohio 45433-7604.
  2. ^ Charles M. Savage (1996). Fifth Generation Management : Co-creating Through Virtual Enterprising, Dynamic Teaming, and Knowledge Networking Butterworth-Heinemann, 1996. ISBN 0750697016. p. 184.
  3. ^ a b c Varun Grover, William J. Kettinger (2000). Process Think: Winning Perspectives for Business Change in the Information Age. p.168.
  4. ^ FIPS Publication 183 released of IDEFØ December 1993 by the Computer Systems Laboratory of the National Institute of Standards and Technology (NIST).
  5. ^ IEEE (1998). IEEE Std 1320.2-1998. IEEE Standard for Conceptual Modeling Language Syntax and Semantics for IDEF1X. New York. p. iii
  6. ^ Bruce, Thomas A. (1992), Designing Quality Databases with IDEF1X nformation Models, ISBN 0932633188 p=xii
  7. ^ a b c Patricia Griffith Friel and Thomas M. Blinn (1989). "Automated IDEF3 and IDEF4 Systems Design Specification Document". Technical report. NASA Johnson Space Center.
  8. ^ a b Perakath C. Benjamin et al. (1994). IDEF5 Method Report. Knowledge Based Systems, Inc.
  9. ^ IDEFØ Overview at idef.com
  10. ^ IDEF1 Overview at idef.com
  11. ^ IDEF1x Overview at idef.com
  12. ^ IDEF3 Overview at idef.com
  13. ^ IDEF4 Overview at idef.com
  14. ^ IDEF5 Overview at idef.com
  15. ^ Mayer, Richard J. ; Griffith, Patricia A. ; Menzel, Christopher P. (1990-91) "IDEF6: A Design Rationale Capture Method Concept Paper" Defense Technical Information Center
  16. ^ Robert P. HanrahanThe IDEF Process Modeling Methodology. Software Technology Support Center. 1995
  17. ^ Observations from a Tech Architect: Enterprise Implementation Issues & Solutions Craig Borysowich. Accessed 20 Jan 2009.

[edit] Further reading

[edit] External links

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