Aspects of Inspection Planning: Quality and quantity

Inspection planning for systems is considered with special emphasis to the effect of the quality of inspections on the system reliability and the probability of repair. Inspection quality is described and discussed in terms of inspection reliability and inspection coverage where the latter is set in relation to the correlation between the failure modes of the considered system. The inspection planning problem is described in general terms taking basis in the Bayesian decision theory. Practical applicable approaches are derived from the more general but also more involving formulations. The theoretical framework for updating of the reliability of components and systems on the basis of inspection results is outlined. Systems representative for inspection planning of different engineering systems subjected to typical deterioration processes are presented. Numerical simulation studies are performed on the presented systems and the effect of inspection reliability and coverage is investigated for systems of different sizes. The results of the studies illustrate the effect of inspections in practical inspection problems and can be used as an initial guideline for selecting the quality of inspections.