A particle swarm algorithm for optimising inspection policies in serial multistage production processes with uncertain inspection costs

Since the quality of products is a major concern in production systems, implementing efficient inspection policies is of great importance to reduce quality-related costs. This article addresses the problem of finding optimal inspection policies in serial multistage production processes to minimise total inspection cost where the cost components are described by the use of fuzzy numbers. The type of inspection in each stage and the acceptance limits are considered as decision variables. The size of sample to inspect, where sampling inspection is adopted, is also incorporated into the model as the third decision parameter. The case in which the inspectors are not error-free is examined, as well. A solution algorithm is proposed based on particle swarm optimisation, and simulation is used to provide better insight into the optimal solution. Numerical experiments discussed in different settings illustrate the applicability and efficiency of the proposed approach.