Method for subcontracting by Fuzzy inference

We propose a method for subcontracting, which judges whether processes of a unit (or part) should be subcontracted or not by multistage fuzzy inference. First, the necessity of the subcontracting of processes such as design and machining is estimated from loads and costs. Secondly, the capacity coefficient of subcontractors is estimated from the quality, cost and due date. Thirdly, on the basis of the necessity and the capacity coefficient of subcontracting, it determines which processes should be subcontracted. Finally, it determines whether we should give an order of processes to one subcontractor or different ones.