Hierarchical and decentralized control for batch and repetitive manufacturing

The evolution of Computer Integrated Manufacturing calls for the organizatlon of complex production processes, obtained by the composition of automated job shops. The larye-scale event-driven nature of such systems requires a revision of the techniques for designing production planning and control architectures. Two manufacturing environments are here considered : batch and repetitive. In the former case, productlon batches are closely related to customer orders so that th eplanning problem consists of scheduling and sequencing the lots through the sequence of shops in order to meet due dates. In the latter case, stationary or slowly varying order quantities must be produced. Then production rates and lot sizes are the main control variables. The paper shows a unified approach to the production planning problem for batch and repetitive manufacturing. Starting from a common model and control architecture, specialized algorithms are derived for the two cases. A hierarchical and decentralized architecture is stressed.