A Note On “Determination of Coordinated Maintenance Scheduling Frequencies For A Group Of Machines”

In this note we present a simpler total cost model when the repair work on a group of machines is coordinated. We demonstrate that coordination of repair work may not be economically beneficial under the generally accepted conditions. We suggest an improvement in the solution procedure in order to consider coordinated as well as uncoordinated repair policies for a group of machines.     

Maintenance Scheduling for Multicomponent Equipment

The problem investigated is the scheduling of preventive and opportunistic maintenance or replacement for equipment with more than one component under conditions of positive failure costs and increasing failure rates for all components. Dynamic programming models are presented for determining optimal policies for two and three component equipment. The resulting optimal policies are compared to commonly used policies and the often substantial diseconomies of such policies are illustrated. The (n,N) policies are found to be near-optimal under a wide range of opportunistic/preventive maintenance costs and failure rates for two and three component equipment. An approach for developing simple (n,N) policies for many component equipment is suggested.     

Gamma Approximation for Preventive Maintenance Scheduling

This paper presents an approximation model for determining minimum cost preventive maintenance schedules where accurate failure data are not available except the “average” (mean) and the “typical” value (mode) of the component lifetime.     

Dynamic Scheduling of a Robot Servicing Machines on a One-Dimensional Line

We examine the operation of a single robot servicing a finite set of machines lined up in succession. Each machine operates for a random time, gets blocked (or fails), waits for the robot, waits for the repair duration, starts operating again, and so on. We seek a dynamic decision rule which at any time, depending on the state of the whole system, will decide what action the robot should take: to repair the machine in front of it, or to move left or right, or to stop and wait. The objective is to maximize the average number of operating machines, over an infinite horizon. This problem arises in die practical context of a textile winding process.

We model this system as a Markov Renewal Decision Process, and present a computational approach, based on dynamic programming, to approximate an optimal decision policy, under the assumption of exponential times to failure. We consider the case in which the robot can stop and change direction anywhere, and the case where the robot can stop or change direction only in front of a machine. Since the optimal policies turn out to be very complex, we examine simpler suboptimal rules, and compare them to the optimal policy and to other previously proposed or commonly used decision rules. For the numerical examples that we have examined, our best suboptimal rules almost always take the optimal decision, and their costs differ from the optimum by a negligible amount. For the case where the robot can stop or change direction anywhere, we used computer simulation to compare the suboptimal rules and conclude that our proposed rules are in general better man those previously proposed or commonly used.     

港口机械智能维护的决策支持方法

围绕集装箱自动化码头建设智能维护服务平台所需的关键技术,研究港口机械的维护决策支持方法,变被动服务为主动服务,实现智能维护理念.结合港机的机构功能,研究了支持维护模式选择的故障模式和后果分析方法;针对设备状态的不确定性,进行了基于不确定概率的故障树定量分析;为支持实现动态维护决策,研究了港机健康指标的灰色预测建模方法.研究结果和工程实践表明,所提出的决策支持方法能有效提高港口机械的可靠性,为管理者能及时了解设备的运行状态并做出维护决策提供有力的支持.     

Optimal Scheduling of Track Maintenance on a Railway Network

To ensure the safety and continued operation of the railway network system, many maintenance and renewal activities are performed on the track every month. Unplanned maintenance activities are expensive and would cause low service quality. Therefore, the track condition should be monitored, and when it has degraded beyond some acceptable limit, it should be scheduled for maintenance before failure. An optimal timetable of the maintenance activities is needed to be scheduled, planning the monthly workload, to reduce the effect on the transportation service and to reduce the potential costs. Considering the uncertainties of the deterioration process, the safety of transportation service, the lifetime loss of the replaced track, the maintenance cost and the travel cost, this article advances an optimisation model for the maintenance scheduling of a regional railway network. An enhanced genetic algorithm approach is proposed to search for a solution producing maintenance schedule such that the overall cost is minimised in a finite planning horizon. A case study is given to demonstrate the application of the method. The case study results were derived by using an enhanced genetic algorithm method, which is specifically developed to deal with the characteristics of the railway maintenance problem. Copyright © 2012 John Wiley & Sons, Ltd.     

基于RCM的港口机械关键设备的维修决策

以港口起重机械为对象,在为振华港机建立的以可靠性为中心的维修决策流程框架下,对所涉及的维修方式进行研究优化.结合故障率调整因子,探索了按有效度最大的原则确定港口机械的最佳预防维修周期的算法;基于P-F间隔,提出了基于RCM的状态维修检测周期算法.最后,开发了可靠性维护系统,通过程序开发,实现各项功能模块.为企业的设备维护提供科学的决策支持.     

汽车维修服务站瓶颈工序的实时调度

在结合优化调度理论和约束理论的基础上,从最小化目标、机器环境、加工特征和约束几方面分析了汽车维修服务站瓶颈工序的实时调度问题的特征,建立了对应的数学模型。根据问题特性,设计了包含复合动态分派规则的启发式调度算法。以实例分析验证了算法的可行性,仿真结果展示了所用算法在优化目标函数值上的优越性和计算时间的可行性。     

Sequencing, Scheduling and Tooling Single-Stage Multifunctional Machines in a Small Batch Environment

Single-Stage multifunctional Machining Systems (SSMSs) are an important integral part of automated, flexible manufacturing systems. However, the SSMS frequently becomes the bottleneck of the entire manufacturing system by virtue of protracted internal set-up requirements. A key aspect of achieving full SSMS utilization is the ability to reduce as much as possible these demands at the expense of increasing external set-up. As of today, fixturing devices have not received much attention in the modeling literature. Nevertheless, fixturing devices are in some cases a limited resource which, may affect the shop scheduling decisions and the shop performance and as such can not be omitted. This study presents a {0–1} programming model which takes the fixturing device's limitation in to consideration when determining the weekly sequence of jobs to be produced. The model tries to minimize the non-productive machine time. Based on this model, a heuristic procedure is developed and tested using data of four production weeks obtained from a hi-tech company that produces medical imaging systems.     

具有成组约束的柔性同序加工车间的排序算法

针对轮胎模具的生产调度特点,研究了具有成组约束的两阶段柔性同序加工车间(FF2)的调度问题,建立了目标函数为最小化最大完成时间的调度数学模型,基于Johnson准则提出一种新的启发式算法,并应用企业的实际算例,说明了数学模型和求解方法的可靠性和有效性。     

面向医疗器械企业灭菌工艺的不同容量平行机批调度

针对医疗器械企业灭菌工艺生产过程的调度问题,提出面向灭菌工艺的不同容量平行机批调度方法,建立以最小化总延迟时长、最小化总加工能耗和最大化灭菌柜装载率为目标的不同容量平行机批调度模型。并针对模型的求解提出一种改进的NSGA-III算法(Improved NSGA-III,INSGA-III)。为了获得更高质量的批调度解,采用EDT+MLC启发式规则生成INSGA-III初始种群,并设计一种局部搜索策略以改进算法迭代后期的搜索能力。最后,通过算例仿真与传统调度方法进行对比分析,验证了该模型和算法的有效性和可行性。结果表明,该模型和算法较传统调度方法有明显的优势,可为医疗企业实际生产调度提供新思路。     

工件带到达时间并具有成组约束的车间排序算法

针对模具制造过程的特点,在工件不同时到达的情况下,研究了前阶段带有成组约束的两阶段柔性同序加工车间的调度问题,建立了目标函数为最小化最大完成时间的调度数学模型．基于Potts的RJ’算法提出解决此类问题的启发式算法,并将该算法应用到轮胎模具企业的生产实例中,通过仿真说明数学模型和求解方法的可靠性和有效性．     

湿式报警阀组的安装、调试及维护管理

湿式报警阀组是湿式自动喷水灭火系统最主要的设备之一,当火灾发生时能迅速地启动消防设备进行灭火,并发出报警信号的设备,它的安装、调试质量直接影响到整个系统能否正常运行.文章对湿式报警阀组的安装、调试,以及日常维护管理作了较详细论述.     

和声搜索算法优化快速消费品生产配送协调调度

研究具有生产准备环节的快速消费品生产配送问题,考虑工厂和配送中心的库存限制,工厂产能限制和劳动力限制,建立一个多周期、多工厂、多产品、多配送中心、多客户的混合整数线性规划模型,旨在最小化准备成本、生产成本、库存成本和配送成本。通过设计一种遗传和声搜索算法对模型进行求解。最后给出一个算例说明所提模型和算法的可行性和有效性。     

A Bayesian Approach to the Scheduling of Preventive Maintenance

This paper presents a Bayesian model for determining minimum cost rate preventive maintenance schedules where historical data are not available. Also, a model to determine appropriate maintenance budgeting policies is presented and discussed.     

集成预防性维护计划的单机调度蚁群优化研究

尽管生产调度与预防性维护计划密切相关,且其共有目标都是提高机床的利用率,但是存在着调度优化上的冲突.为了综合考虑单机情形下的生产调度与预防性维护计划,提出了一种改进的蚁群优化算法,用于解决以总计作业加权完成时间和总计维护成本最小为双目标的生产调度与预防性维护计划的集成模型.同时进行了大量的仿真实验,比较结果表明提出的蚁...     

A Computer-Aided Graphical Procedure for Scheduling Preventive Maintenance of Electric Power Generating Units

This article attempts to show how computer graphics can assist in computerized development of project-type schedules as exemplified by preventive maintenance scheduling in the electric power industry. The method is equally applicable to the scheduling of maintenance activities in general or, with modification, to devising shift schedules for personnel such as police, nurses, and toll collectors who must provide 24-hour service with changing demand levels. A hand procedure currently used by electric utilities for creating preventive maintenance shutdown schedules for generator units is first described. A mixed integer programming model of the problem is given which is computationally intractable for any realistic-size problems. The same problem using man-machine interaction via a graphics terminal to overcome the computational limitations of the mathematical formulation is then described and illustrated. A proposed extension to improve the speed of solution is also described.     

基于瓶颈的制造单元两阶段群组调度程序与仿真

为解决具有瓶颈的制造单元调度问题,提出了一种以瓶颈为基础的两阶段群组调度方法.该方法充分运用瓶颈机器,使所有零件的最大完成时间最小化.为评估调度方法的绩效,文章建立了两阶段群组调度程序的5机制造单元仿真模型.仿真实验结果证明,本方法不仅平均总完工时间最短,而且是绩效表现最稳定的调度方法.     

Using Utility Functions for Aggregate Scheduling in Health Maintenance Organizations (HMO'S)

The multiple attributes and characteristics of the services provided by a health maintenance organization (HMO) are reduced to a common unit of measurement by means of utility functions. This reduction allows the development of a micro-economic aggregate planning model that can be used both for the short and the long term to make optimizing decisions on system inputs and resource allocations. The model is designed to deal with the common revenue- and budget-constrained situations and is directed to maximize the level of service provided by the HMO, according to the management's perceptions of the system characteristics. An empirical short term application of the model is presented and compared against actual management decisions. Data needs and implementation requirements are discussed, along with the managerial implications of this approach.