| Summary: | 碩士 === 元智大學 === 工業工程與管理學系 === 102 === The purpose of this paper is to investigate integration of preventive maintenance and x-bar control chart by simulation. We consider μ may be shift because manufacture process occurs exception, we assume the time of manufacture process occurs exception is submit exponential distribution, in order to maintain process stability, we integrate preventive maintenance and discuss the time of performing preventive maintenance. We perform preventive maintenance not only at a certain point of time but also we find the sample point presents a non-random situation. In this paper, if we find consecutive sample points on the same side of the control chart’s centerline, we perform preventive maintenance. We assume the manufacturing process will renew after performing preventive maintenance. We compare the difference between integrated preventive maintenance and not integrated preventive maintenance, and establish the best time point of preventive maintenance. The optimal solution of the cycle time and cost is not easy to obtain so we discuss the ARL and cost per unit of time by simulation. We find parameter m, k, r, λ are inversely proportional to ARL and the times of preventive maintenance. If the λ value is smaller, parameter m, k are inversely proportional to the cost. The parameter n, r, λ are proportional to the cost per unit of time. From the simulation results, the ARL of integrated preventive maintenance is longer than the ARL of non-integrated preventive maintenance, but the cost per unit of time is less. We summarized the optimum number of samples and the time point of maintenance.
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