Quick decision-making support for inspection allocation planning with rapidly changing customer requirements

Manufacturing products with multiple quality characteristics is always one of the main concerns for an advanced manufacturing system. To assure product quality, finite automatic inspection systems should be available and employed. Inspection planning to allocate inspection stations should then be performed to manage limited inspection resources. Since product variety in batch production or job shop production is increased to satisfy the changing requirements of various customers, the specified tolerance of each quality characteristic varies from time to time. Except for a finite inspection resource constraint, therefore, manufacturing capability, inspection capability, and tolerance specified by customer requirement are considered concurrently in this research. A unit cost model is constructed to represent the overall performance of an advanced manufacturing system. Both the internal and external costs of a multiple quality characteristic product are considered. The inspection allocation problem can then be solved to reflect customer requirements. Since determining the optimal inspection allocation plan seems to be impractical as the problem size gets larger, in this research, two decision criteria (i.e., sequence order of workstation and tolerance interval) are employed concurrently to develop a heuristic method. The performance of the heuristic method is measured in comparison with an enumeration method that generates the optimal solution. The result shows that a feasible inspection allocation plan to meet changing customer requirements can be determined efficiently.