Evaluating the performance of variable scheme X-bar control chart: a Taguchi loss approach

The concept of loss function has been combined, with a numerous statistical decision models which require quality cost estimation. Moreover, estimation of the costs of non-conforming product is one of the most important inputs in economic design of control charts. Therefore, on the basis of Markov chain approach, this paper focused on extending control chart with variable schemes control charts by considering Taguchi's quality loss function. Afterwards, control chart parameters are defined in such a way to minimise the cost of process monitoring via genetic algorithm. Sensitivity analysis on the different sizes of the process shift and the cost of rework or scrap a product and comparing the results unfold insights that will help the quality engineers in designing the most powerful plans for the process.