Due-Time Performance in Production Systems with Finished Good Buffers: A Systems Approach

在机器不可靠的生产系统中，在固定时间间隔内生产的零件数量是一个随机变量。它的分布既体现了产量的特点，又体现了产量的变异性。许多出版物都对产量进行了分析。相比之下，在最近的几篇文章中对生产变异性进行了研究，其中大部分都讨论了生产变异性。尽管它是一种有用的业绩衡量标准，但它只提供了生产变异性的一般理论特征。事实上，对差异的了解还不能具体说明满足固定装运计划的概率。最近，引入了一种新的可变性度量，称为交货期绩效(DTP)，定义为满足发货计划的概率。这个项目的目标是从DTP的角度开发生产系统的分析和设计方法，并将这些方法应用于汽车工业。具体地说，将解决以下分析问题：给定一个生产系统，为DTP评估开发一种建设性的分析技术。将调查两个设计问题。直接问题：考虑到机器的可靠性特点以及客户对发货间隔和发货大小的要求，设计一个产品交付系统，以满足DTP要求。逆问题：给定客户需求和产品交付系统，确定满足给定DTP所需机器的可靠性特性。如果成功，该项目将为拉动式精益制造环境下生产系统的分析和设计提供严格的工程工具。它们的实现将导致“计算”产品交付系统的可能性，而不是根据当今使用的特别技术来选择它。

In production systems with unreliable machines, the number of parts produced during a fixed interval of time is a random variable. Its distribution characterizes both the production volume and the productionvariability. The production volume has been analyzed in many publications. In contrast, the production variability has been studied in just a few recent articles where mostly production variance has been addressed. Although a useful measure of performance, it offers only a general, theoretical characterization of the production variability. Indeed, knowledge of the variance does not yet specify the probability with whicha fixed shipping schedule is satisfied. Recently, a new variability measure, referred to as the Due-Time Performance (DTP) and defined as the probability to satisfy a shipping schedule, has been introduced. The goal of this project is to develop methods for analysis and design of production systems from the point of DTP and to apply these methods in the automotive industry. Specifically, the following analysis problem will beaddressed: Given a production system, develop a constructive, analytical technique for DTP evaluation. Two design problems will be investigated. Direct problem: Given the reliability characteristics of the machines and the customer requirements on the shipping interval and shipment size, design a product delivery system so that DTP requirements are satisfied. Inverse problem: Given the customer requirements and the product delivery system, determine reliability characteristics of the machines required to satisfy a given DTP. If successful, this project will provide rigorous engineering tools for analysis and design of production systems in lean manufacturing environment operating in the pull regime. Their implementation will leadto a possibility of "calculating" a product delivery system rather than selecting it on the basis of ad hoc techniques in use today.