Inspection for circuit board assembly

Several stages of tests are typically performed in circuit board assembly, and each test consists of one or more noisy measurements. We consider the problem of jointly optimizing the allocation of inspection and the testing policy in a system with a predefined inspection configuration; that is, at which stages should a board be inspected, and at these stages, whether to accept or reject a board based on noisy test measurements. The objective is to minimize the expected costs for testing, repair, and defective items shipped to customers. We analyze the problem and document an application of the model to an industrial facility. Since we were unable to gather all the necessary data, the model was applied in a limited and piecemeal fashion. Nevertheless, the proposed policy significantly improves upon the facility's historical policy.