Serial Inspection Plan in the Presence of Inspection Errors: Maximum Likelihood and Maximum Entropy Approaches

A high-quality inspection must ensure most of the detectable faults are, indeed, detected. In practice, however, the effectiveness of inspections varies widely from inspector to inspector and, in some cases, multiple inspectors are assigned to inspect the same product in a sequential manner. For such a serial inspection, we propose two new methods that can estimate the number of undetected faults in the product. In a numerical analysis, we compare the performances of the maximum likelihood estimator and the maximum entropy method with that of an existing method. The maximum entropy method is shown to perform very well, particularly when the detection probabilities are not the same among the inspectors.