IDEF: Семейство языков моделирования для системной инженерии

Family of modeling languages
the defense fair

IDEF, initially an abbreviation of ICAM Definition and renamed in 1999 as Integration Definition, is a family of modeling languages in the field of systems and software engineering. They cover a wide range of uses from functional modeling to data, simulation, object oriented analysis and design, and knowledge acquisition. These definition languages were developed under funding from U. S. Air Force and, although still most commonly used by them and other military and United States Department of Defense (DoD) agencies, are in the public domain. The most widely recognized and used components of the IDEF family are IDEF0, a functional modeling language building on SADT, and IDEF1X, which addresses information models and database design issues.

The IDEF0 functional modeling method is designed to model the decisions, actions, and activities of an organization or system. 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. 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. 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 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.

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 predicts what a system will do. The latter was the focus of IDEF2, the former is the focus of IDEF3.

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. 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 IDEF5 Ontology Capture Method has been developed to reliably construct ontologies in a way that closely reflects human understanding of the specific domain.

IDEF6, or integrated definition for design rationale capture, is a method to facilitate the acquisition, representation, and manipulation of the design rationale used in the development of enterprise systems. Rationale is the reason, justification, underlying motivation, or excuse that moved the designer to select a particular strategy or design feature. More simply, rationale is interpreted as the answer to the question, “Why is this design being done in this manner?” Most design methods focus on what the design is (i. e. on the final product, rather than why the design is the way it is).

IDEF8, or integrated definition for human system interaction design, is a method for producing high quality designs of interactions between users and the systems they operate. Systems are characterized as a collection of objects that perform functions to accomplish a particular goal. The system with which the user interacts can be any system, not necessarily a computer program. Human system interactions are designed at three levels of specification within the IDEF8 method. The first level defines the philosophy of system operation and produces a set of models and textual descriptions of overall system processes. The second level of design specifies role centered scenarios of system use. The third level of IDEF8 design is for human system design detailing. At this level of design, IDEF8 provides a library of metaphors to help users and designers specify the desired behavior in terms of other objects whose behavior is more familiar. Metaphors provide a model of abstract concepts in terms of familiar, concrete objects and experiences.

IDEF9, or integrated definition for business constraint discovery, is designed to assist in the discovery and analysis of constraints in a business system. A primary motivation driving the development of IDEF9 was an acknowledgment that the collection of constraints that forge an enterprise system is generally poorly defined. The knowledge of what constraints exist and how those constraints interact is incomplete, disjoint, distributed, and often completely unknown. Just as living organisms do not need to be aware of the genetic or autonomous constraints that govern certain behaviors, organizations can (and most do) perform well without explicit knowledge of the glue that structures the system. In order to modify business in a predictable manner, however, the knowledge of these constraints is as critical as knowledge of genetics is to the genetic engineer.

IDEF14, or integrated definition for network design method, is a method that targets the modeling and design of computer and communication networks. It can be used to model existing ("as is") or envisioned ("to be") networks. It helps the network designer to investigate potential network designs and to document design rationale. The fundamental goals of the IDEF14 research project developed from a perceived need for good network designs that can be implemented quickly and accurately.