Integrated Optimization Modelling in Quality Control, Production Planning, Inventory Control and Maintenance

今天的行业主要专注于提高生产率和质量。制造过程成功的关键是质量控制、生产计划、库存控制和维护政策的适当整合，直到最近，这些都被视为独立的问题。提出的研究提出了综合优化模型来解决各种生产和质量控制问题。本研究由四组问题组成，既有实践意义，又有理论意义和训练价值。 第一套涉及工艺参数和生产运行的联合经济选择。这个问题的出现是因为它会影响客户产生的不良率、材料成本、报废或返工成本以及质量损失。在生产期间，工艺参数设置可能转变为失控状态。设定最优工艺目标参数(S)和确定最优生产运行是许多工业过程的两个非常重要的因素。这些因素的有效结合将为制造商提供经济优势。预计这项研究的结果将对最终用户非常有用。 第二组提出了恶化生产系统的质量控制、生产控制和预防性维护的综合经济模型，在该模型中，生产过程不仅可能从受控状态转变为失控状态，而且可能在任意时刻发生故障。控制图的经济设计是指为了选择使质量成本最小的控制图参数而对成本模型进行优化。制造设备的预防性维护和制造产品的质量是相互关联的。所提出的综合模型研究将在一般班次、故障和维修时间分布下进行。本研究可望在该领域做出重大贡献。 第三组是建立了一个动态集成模型，用于对具有变质库存的不完美生产过程的生产数量、检验调度和质量控制进行联合优化。对于产品质量和生产数量同等重要的制造商，提出了库存、质量和维护问题的广义综合经济模型。 第四组是建立了一个综合模型，用于确定随机分布产品的最经济生产量、最优保修成本、最优保修期和最优价格。这是一个新的调查领域，将分析库存、质量和维护的集成如何影响保修政策。这将表明，纠正性维护政策将大大减少保修索赔。

Today's industry is mainly focused on improving productivity and quality. The key to success in manufacturing processes is the proper integration of quality control, production planning, inventory control, and maintenance policy, which have been treated as separate issues until recently. The proposed study presents integrated optimization modelling for solving various production and quality control problems. The research consists of four sets of problems which have practical and theoretical importance as well as training merit. The first set involves the joint economic selection of process parameters and production run. This issue arises because it can affect the defect rate, material cost, scrap or rework cost and quality loss incurred by the customer. During the production period, the process parameters setting may shift to an out-of-control state. Setting the optimal process target parameter(s) and determining an optimal production run are two very important factors for many industrial processes. Effective integration of these factors will provide an economic advantage to the manufacturer. It is expected that the findings of this research will be very useful for end users. The second set proposes integrated economic models for quality control, production control and preventative maintenance for a deteriorating production system in which the production process 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. The economic design of control charts refers to the optimization of cost models for the purpose of selecting control chart parameters which minimize the cost of quality. The preventative maintenance of manufacturing equipment and the quality of a manufactured product are inter-related. The proposed research on integrated models will be formulated under general shift, breakdown and repair time distributions. This research is expected to make a significant contribution in the field. The third set is the development of a dynamic integrated model for joint optimization of production quantity, inspection scheduling, and quality control for an imperfect production process with deteriorating inventory items. A generalized integrated economic model for inventory, quality, and maintenance problems will be presented for the manufacturer, for whom the product quality and the production quantity are equally important. The fourth set is the development of an integrated model for determining the most economic manufacturing quantity, the optimal warranty cost, the optimal warranty period and the optimal price for a random lifetime distributed product. This is a new area of investigation which will analyze how integration of inventory, quality and maintenance can affect warranty policies. It will be shown that the corrective maintenance policy would considerably reduce warranty claims.