Dissertação apresentada na Faculdade de Ciência e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresCustomers demand for high product customization and differentiation, and short product life-cycle. As such, industries have to adapt their manufacturing systems more frequently in order to remain competitive. Changing manufacturing systems within a short period of time requires a huge effort in terms of time and money, reducing this effort would make industries more competitive. The proposed solution consists in developing an ontology-based multi-agent system to control manufacturing systems. Defining the ontology for the manufacturing system allows the control to perform its operation, and when changes arise, it is required to change the ontology so that the control became aware of the changes to control the manufacturing system. An ontology-based control allows for a smaller setup time since the control is not specific for one physical system and can be applied to different ones, therefore it reduces the effort in adapting manufacturing systems to required changes allowing industries to became more competitive. Flexibility is given by the multi-agent system that controls the physical system with the ontology. Stating this, the solution of an ontology-based control for manufacturing systems provides the required results
