Integrated production, quality and maintenance models under various preventive maintenance policies.

Abstract

Production, quality and maintenance are the three important aspects in any industrial process. Many attempts have been made in the literature to develop models which integrate them. However, these aspects have been generally treated separately. This thesis presents three integrated models for economic production quantity and economic design of control charts under various preventive maintenance (PM) policies. Taguchi's quadratic loss function is also incorporated into the development of the economic design of control charts for processes having general shift to failure distribution. A computer package to simulate all of the integrated models is developed. Computational results of various PM policies demonstrated that incorporating PM into production processes yields improvement in the product quality and consequently reduction in the total expected cost. Also, it demonstrated that incurring additional cost for performing PM might not be justifiable if the cost of PM is high to the point where it is not compensated for by the reductions in the quality control cost. Moreover, sensitivity analysis was conducted to study the effect of important parameters on the developed models.