Special Session on Writing Patterns

Software patterns represent a promising research area in reason of the subsequent benefits of its application, mainly in terms of productivity reached with the reuse. In automatic, architectural patterns can be applied in recurrent problems involving diverse types of computational systems. A complex application, for which architectural patterns can bring great contribution, is the Supervisory Control of Automated Manufacturing Systems (SC-AMS). Copyright (c) 2002, Jean Marcelo Simão, Marcos Antonio Quináia, Paulo Cézar Stadzisz. Permission is granted to copy for the SugarloafPLoP 2002 Conference. All other rights reserved. This article proposes an architectural pattern for SC-AMS that takes care of the functional requirements gotten through the analysis by use cases diagrams. This analysis considers specific use cases diagrams whose recurrences are presented in generic use cases diagrams, employing an UML extension as notation. The conception of the architectural pattern components is carried out with a certain generalization degree, since that the generic functional requirements are established. These components of the model are firstly specialized aiming to solve specific requirements and, subsequently, they are generalized to comprise recurrent elements in a wide abstraction degree. As particular feature, the architectural pattern presents a model of Monitoring/Command, conceived in a class hierarchy, and a model of Decision/Coordination that establishes, in generic terms, a causal logic in which the evaluation and correlation of states (observed in the monitoring) implies in a sequence of orders (activating commands). The causal logic in the architectural pattern is expressed in the form of a generic Rule Based System for SC-AMS. Each system of Supervisory Control instantiated from the considered architectural pattern presents groups of objects understood as agents, therefore consisting in an Expert System carried out by reactive and cooperative agents.