Ultrasonic arrays are now used routinely for the inspection of engineering structures in order to maintain their integrity and assess their performance. Such inspections are usually optimised manually using empirical measurements and parametric studies which are laborious, time-consuming, and may not result in an optimal approach. In this paper, a general framework for the optimisation of ultra...

The manufacturing of critical applications often requires a low or zero defect level. To ensure quality is not compromised when high product reliability is required, quality-engineering departments frequently employ 100% inspection. Given the fallibility of human inspectors though, re-inspection procedures, at times, may have to be implemented. This paper analyzes various multi-inspector scenar...

The paper develops integrated production, inventory and maintenance models for a deteriorating production system in which the production facility may not only shift from an ‘in-control’ state to an ‘out-of-control’ state but also may break down at any random point in time during a production run. In case of machine breakdown, production of the interrupted lot is aborted and a new production lot...

⎯This paper investigates the case where a failed product can be detected only through inspections. During the lifetime of the product, it is inspected once and then must be replaced by either corrective or preventive replacement depending on the result of the inspection. By incorporating a discount factor, a mathematical model is established to take the time value of costs into account. Based o...

In this paper, a single-product, single-machine system under Markovian deterioration of machine condition and demand uncertainty is studied.  The objective is to find the optimal intervals for inspection and preventive maintenance activities in a condition-based maintenance planning with discrete monitoring framework. At first, a stochastic dynamic programming model whose state variable is the ...