A Model-Based Engineering Workbench for Shop Floor Control Applications

Abstract

The work described in this paper was undertaken at the INESC Porto Manufacturing Systems Engineering Unit. An overview of PROFIT, a commercial product, and the outcome of the ESPRIT project 5478 Shop Control, is the starting point of this paper. This introduction gives a special emphasis to the PROFIT modelling environment supported by Simple++, a state-of-the-art object oriented modelling and simulation tool, and to its integrating infrastructure. Further improvements in the PROFIT modelling environment were motivated by the need of a software modelling language, not provided by Simple++. Our basic objective was to enhance its modelling facilities by allowing the construction of integrated information and material flow models. This target led to the construction of the Modelling Workbench (MW), resulting from the integration of a formal description language (Specification and Description Language - SDL) modelling primitives into Simple++, which is then presented in this paper. Further improvements in the MW were achieved with the additional development of “SDL-based” techno-organisational modelling constructs. More recent developments on the MW are then presented, they were mainly related with the SDL modelling facilities ease of use, leading to its integration with a CASE tool. This fostered the use of an agent-based approach to software development, by introducing the concept of a software Lego, whose building blocks were organised as a library, of both data and processes, for re-use in the creation of new software models. This concept, which is not new, gained extra relevance through the combination of the CASE tool and the object oriented software modelling and simulation environment provided by the modelling workbench. This paper closes with our view on how the Modelling Workbench fits into the Purdue Enterprise Reference Architecture, by illustrating the usage of its tools along the “shop floor control system” engineering life-cycle.