A Basic Study on Cost-based Scheduling in Job Shop for Agile Manufacturing

摘要

Considering the cost is the most important criterion for manufacturing industries especially seeking the agility, we propose to employ the manufacturing cost at shops to evaluate the schedule as a replacement of conventional measures based on time and/or quantity. The method is named the cost-based scheduling. For cost estimation, the activity based costing method (ABC) is introduced in this study. The ABC is widely accepted in the industries as an accounting method but we consider it as an efficient index reflecting the real performance of the manufacturing shops. In this study, we firstly consider a single machine scheduling problem. By comparing the optimum schedule with respect to various measures, it is shown that the cost based scheduling method can cope with the multi-objective circumstance by representing the circumstance by appropriate cost structure and parameters. Then we apply various dispatching rules to a job shop model which is based on a real factory and evaluate them by various measures, i.e., makespan, total flow time, average lateness and number of late jobs. Following a brief description of ABC method, the method is applied to the model. By simulation of the model factory with various dispatching rules and some sets of cost parameters, the production costs are estimated for each case. The results are compared and discussed demonstrating the effectiveness of cost-based scheduling.