Operation allocation and part type selection in E-manufacturing: An auction based heuristic supported by agent technology

This paper enlightens some of the key issues involved in developing real schedule generation architecture in E-manufacturing environment. The high cost, long cycle time of development of shop floor control systems and the lack of robust system integration capabilities are some of the major deterrents in the development of the underlying architecture. We conceptualize a robust framework, capable of providing flexibility to the system, communication among various entities and making intelligent decisions. Owing to the fast communication, distributed control and autonomous character, agent-oriented architecture has been preferred here to address the scheduling problem in E-manufacturing. An integer programming based model with dual objectives of minimizing the makespan and increasing the system throughput has been formulated for determining the optimal part type sequence from the part type pool. It is very difficult to appraise all possible combinations of the operation-machine allocations in order to accomplish the above objectives. A combinatorial auction-based heuristic has been proposed to minimize large search spaces and to obtain optimal or near-optimal solutions of operation-machine allocations of given part types with tool slots and available machine time as constraint. We have further shown the effects of exceeding the planning horizon due to urgency of part types or over time given to complete the part type processing on shop floor and observed the significant increase in system throughput.