Category: Type 1 Model

Comments: Another work performed at the GRAI laboratory was the extension of the GRAI method to GRAI-GIM (GRAI Integrated Methodology) within the framework of the ESPRIT Project 418, Open CAM system and ESPRIT Project 2338, IMPACS [36,37]. GRAI-GIM contains a user-oriented method and a technically-oriented one (See Fig. 4.14). The user-oriented method transforms user requirements into user specification in terms of function, information, decisions and resources. The technically-oriented method transforms the user specification into technical specifications in terms of information and manufacturing technology components and the organization. The technical specification must allow the implementor to choose (buy, commission, or develop) all the components needed to implement the system. A computerized support tool knows as CAGIM (Computer Aided GIM) is being developed at the GRAI Laboratory within the framework of the IMPACS project on Unix systems with X-Windows, to support the GRAI-GIM method.

[36] Vellespir, B., Doumeingts, G., and Zanettin, M., 'Proposal for an Integrated Approach to Model and Design Manufacturing Systems', Proceedings, Third International Conference on Computer Application in Production and Engineering, CAPE '89, Tokyo, Japan (October 2-5, 1989). Published by North Holland.

[37] Zanettin, M., and Doumeingts, G., 'The GIM Method for CIM System Analysis', for Advanced Studies in Systems Research and Cybernetics, International Institute for Advanced Studies in Systems Research and Cybernetics, Baden Baden, Germany (August 1992).

Similar work on methods was also carried out in Europe, notably the GRAI method [7] and MERISE method [11]. Before developing the GRAI method, some existing works had been reviewed, notably SADT and SSAD methods. It was found that the decisional aspects were not very well taken into account in these methods. So, it was important for the GRAI method particularly to deal with the decisional aspects of manufacturing systems. Based on the GRAI models, two formalisms were developed to model the macro decision structure and the micro decision center; the GRAI grid and the GRAI nets. A structured approach was defined to show how to apply the method. The GRAI method has been transferred to industry (over 100 industrial applications).

[2] Doumeingts, G., Vallespir, B. Darracar, d. And Roboam, M., 'Design Methodology for Advanced Manufacturing Systems,' Computers in Industry, Vol. 9, No. 4, pp. 271-296 (December 1987).

[3] Doumeingts, G., Vallespir, B., Zanettin, M., and Chen, D., GIM, GRAI INTEGRATED METHODOLOGY, A Methodology for Designing CIM Systems, Version 1.0, Unnumbered Report, LAP/GRAI, University Bordeaux 1, Bordeaux, France (May 1992).

[7] Doumeingts, Guy, Methode GRAI: Methode de Conception des Systemes de Productigue, These d Etat en Automatigue, Universite de Bordeaux 1, Bordeaux, France (November 1984)

< DIAGRAM GOES HERE >

The GRAI model is a reference through which various elements of real world can be identified. The macro conceptual model is used to express one's perception and ideas on the manufacturing system which is decomposed into a decision subsystem, an information subsystem and a physical subsystem. Particularly within the decision subsystem one finds a hierarchical decision structure composed of decision centers. Decision centers are connected by a decision frame (objectives, variables, constraints and criteria for decision making). The operating system is an interface between the decision system and the physical system. The micro conceptual model is used to represent the internal elements and structure of the decision center