Modelling quality in replacement and inspection maintenance

Heterogeneity in component and maintenance quality is considered in the context of age-based inspection and replacement for a single component system. A three-state component failure model is assumed, with a defective state preceding the failed state. Heterogeneity in maintenance intervention is modelled by supposing that inspections may induce the defective state. Component heterogeneity is modelled by supposing that the population of components comprises a mixture of the weak and strong, and that the mixing proportion and cost of components vary between suppliers. Within this framework, the impact, on system reliability and cost, of switching component or maintenance supplier is determined. Broadly, our finding is that one is much more inclined to switch supplier in order to obtain higher quality maintenance than to obtain higher quality components. A gas pressure control valve is used to illustrate our ideas.     

An Annotated Bibliography of Estimation Procedures Useful in Engineering Economy

Standard decision analysis involves the folding-back of decision trees. This paper provides a simpler approach to evaluating decision trees. It is shown that under certain conditions two-stage trees may be evaluated by inspection of the trees and their probability distributions. Examples are presented of practical problems in which this technique is used.     

Investigating the decision criteria used in electronic components procurement

Previous research has reported that the decision criteria used to evaluate suppliers differs by product category. Rather than investigating the “key buying criteria” across the entire gamut of products and services, this research takes a novel approach by investigating the evaluation criteria used in the procurement of component parts. The survey results suggest that the content and structure of the decision criteria used by business customers to assess their suppliers does not differ across an array of electronic components. The business implication is that business customers that formally track the performance of their suppliers along the critical evaluation criteria will be in a better position to gain a competitive advantage by effectively managing the inbound supply chain.     

Short-term decision support system for maintenance task prioritization

Maintenance operations have a direct influence on production performance in manufacturing systems. Short-term production analysis is imperative to enable manufacturing operations to optimally respond to dynamic changes in the system behavior. However, most of the conventional decision support systems for production and maintenance focus on long-term statistic analysis, which is usually not applicable to a short-term period. Maintenance task prioritization is crucial and important for short-term analysis to reduce unnecessary or improper maintenance activities, especially when availability of maintenance resources is limited. The existing methods for maintenance priority assignment are often through heuristic methods or experience, which could cause unscheduled downtime and production losses. In this paper, a short-term decision support system for maintenance task prioritization based on the system operating conditions is introduced. The impact factor for priority assignment is obtained theoretically. A case study based on the simulation of an automotive assembly line illustrates that the proposed short-term system improves the system performance with a lower cost than the long-term method.     

Optimal lot sizing in a non-cooperative material manager-controller game

It is important for manufacturing companies to optimise purchase order quantities. Inaccurate lot size planning raises costs and lowers profits, which top management of course attempts to avoid through controlling processes. The lot size decision becomes even more relevant in the case of just-in-time delivery within a supply chain.The interaction between lot sizing and auditing can be described in terms of a modified inspection game. This paper considers how probabilities, which are the basis for the mixed strategies at equilibrium in the inspection game, will change if the level of penalties accruing to the two players (material manager and controller) depends on the cost deviation caused by the material manager's poor lot-size planning. It is evident that the Nash equilibrium shifts to the strategy combination (methodically determined decision and low auditing level), if the penalties imposed on the controller and material manager increase.Penalties that depend on such deviations, and an accurate audit of the controller's report by top management, prove to be the best instruments for avoiding mismanagement by the material manager and poor controller work, both of which lead to high costs.     

Toward understanding strategic issue diagnosis

This paper calls attention to a central but neglected process in strategic decision making, i.e. strategic issue diagnosis (SID). A framework for discussing SID is presented in terms of three critical components: inputs, process characteristics and outputs. The framework is illustrated in the context of PIMS and BCG, two widely recognized strategy models. The major implications highlight the theoretical significance of SID for understanding strategic decision making.     

影响检泵作业质量的因素剖析及对策

通过对检泵维修的日常工序管理及影响检泵维修质量的客观因素及关键部件工况环境的分折,寻找出提高检泵作业质量的有效途径。制定出切实可行的对策措施,全方位的提高检泵维修质量水准。     

基于失效风险的建筑物预防维修成本模型优化

建筑物预防性维修成本的最优控制问题,是企业现代化经营管理的一个重要组成部分,直接影响到企业的经济效益。针对承受重复荷载作用的建筑构件,失效概率随服役时间增加而增大的实际情况,提出了失效风险的概念。采用役龄回退因子描述了维修后失效概率降低的程度,在此基础上推算出满足可靠度约束条件,适用于特定时间段非等间隔检测期序列,计算出单位维修周期内的检测次数。通过对维修成本函数的分析,建立了基于等失效风险状态的维修成本优化模型。为房屋物业管理部门进行建筑物的维修和更换决策提供参考依据。     

销售合同管理信息系统的分析与设计

本文介绍了销售合同管理信息系统。利用微机对合同进行管理,能够提高工作效率,及时查询合同执行情况,及时了解全厂的销售情况,并对各个客户的重要程度进行定量化的分析,为领导决策和外销员的工作提供必要信息。     

Resale Externality and the Used Housing Market

The selling prices of used houses may not fully reflect the maintenance spending of current owners when prospective buyers are unable to conduct a thorough inspection before purchase. This article investigates how this resale externality problem affects the maintenance expenditures of homeowners. After considering both observable and unobservable repair expenses, the analysis shows that the resale externality reduces not only maintenance expenditures, but also household mobility. A treatment effects model is used to estimate the simultaneous relationship between mobility and maintenance in the Japanese resale housing market. The results indicate that the resale externality has a significant negative impact on maintenance expenditures.     

On Reliability Evaluation of Multistate Weighted k-out-of-n System Using Present Value

A new reliability evaluation methodology for multistate weighted k-out-of-n systems is presented in this article. The present value of the cash flow generated by the system components is used as a reliability value. We take a financial view of reliability and consider functioning periods and the time value of money in system reliability analysis. Two approaches, the universal generating function (UGF) and recursive algorithm, are applied to evaluate the reliability of the multistate weighted k-out-of-n system. An illustrative example is calculated based on the proposed system reliability evaluation methodology. It is shown that this evaluation method can also be used to find the value of the maintenance policy. Finally, the UGF and recursive algorithm approaches are compared with each other for large system reliability assessment.     

Developing and using a customer profile data bank

This article proposes the implementation of a customer profile system to aid the industrial marketer in: making daily sales decisions involving the firm's customers; the development of the vendor's “buyer mix”; and the production of marketing analysis reports used by the firm. The components of the customer profile are presented and the procedures by which these elements can be incorporated into the firm's decision making are explained. Working examples are also provided to reinforce the concepts. Unfortunately the names of the actual corporations had to be deleted or changed for reasons of confidentiality.     

计算机广域网网络扩容方案

通过分析某公司总部与各地市分支机构互联的网络结构,结合总部网络维护人员提出的需求,针对目前的网络现状及其存在的弊端,提出了网络扩容方案,分支机构与总部由原来的一条2 Mbit/s线路互联扩容为2条,形成了双线路、双设备的负载分担和冗余机制,实现了2条线路互为备份、自动切换的目标,保障了网络的安全性和可靠性。     

National food safety control systems in Sub-Saharan Africa: Does Uganda’s aquaculture control system meet international requirements

Stringent food safety requirements set by developed country markets, which require exporting countries to establish effective national food control systems (NFCS) that guarantee safety of the products to the market, pose a challenge to Sub-Saharan countries in development of aquaculture products as alternative exports following the decline of capture fisheries. In the study, four components of Uganda’s NFCS including legislation, competent authority, inspection services, and laboratory services were evaluated for compliance with FAO/WHO, European Union (EU), and the United States (US) market recommendations for guaranteeing aquaculture product safety. Using a checklist, component elements were benchmarked and scored, and components ranked for compliance with the recommendations. On a scale of 0–5, where 0 denotes none, 1 very low, 2 low, 3 some, 4 almost total, and 5 full compliance, only laboratory services had a barely acceptable score of 3.3 (some compliance). The rest including legislation which is central in setting the level of controls by the other three components scored below three, and the combined score for all components was only 2.2, indicating that Uganda’s NFCS was still short of the requirements to allow entrepreneurs to access markets in the EU and other developed countries. The low score is partly attributed to the dynamics of this country’s fledgling aquaculture industry and the rapidly evolving food safety requirements in the international markets.     

Development of maintenance function performance measurement framework and indicators

The performance and competitiveness of manufacturing companies is dependent on the reliability, availability and productivity of their production facilities. To ensure the plant achieves the desired performance, maintenance managers need a good track of performance on maintenance process and maintenance results. This can be attained through development and implementation of a rigorously defined performance measurement framework and indicators that are able to measure important elements of maintenance function performance. The purpose of this paper is to demonstrate that performance indicators are not defined in isolation, but should be the result of a careful analysis of the interaction of the maintenance function with other organisational functions, most evidently with the production function. In this paper, a conceptual framework that provide guidelines for choosing maintenance function performance indicators is proposed. It seeks to align maintenance objectives with manufacturing and corporate objectives, and provides a link between the maintenance objectives, maintenance process/efforts and maintenance results. Based on this conceptual framework, performance indicators of the maintenance process and maintenance results are identified for each category.     

Assessing introduction factors for a new industrial product

The present research involves determinant component analysis [3]. Specifically, the study assesses which components—price, product or environmental—are most important in the design of new entry strategy. Under conditions of abundance, industrial firms primarily analyzed price and product characteristics when making new product decisions. In choosing one supplier over another the stalwart buying motives have been quality, service and price [4]. However, these decision components were conceptualized in a period of abundance. Under conditions of scarcity, are price and product characteristics still important? Are environmental dimensions perhaps more important under shortage conditions when making new product decisions? Besides describing the key components that may be considered in new product programming, the article also outlines an approach that may be used to find determinant decision components.     

A case study of condition based maintenance modelling based upon the oil analysis data of marine diesel engines using stochastic filtering

This paper presents a case study of condition based maintenance modelling based on measured metal concentrations observed in oil samples of a fleet of marine diesel engines. The decision model for optimising the replacement time of the diesel engines conditional on observed measurements is derived and applied to the case discussed. We described the datasets, which were cleaned and re-organised according to the need of the research. The residual time distribution required in the decision model was formulated using a technique called stochastic filtering. Procedures for model parameter estimation are constructed and discussed in detail. The residual life model presented has been fitted to the case data, and the modelling outputs are discussed.     

Product profile analysis: A tool for industrial selling

The purpose of this article is to provide a step-by-step approach to how product profile Analysis (PPA) can be applied to industrial selling. Specifically, the sales representative can use PPA to help the prospective buyer identify the key criteria involved in the purchasing activity. The concentration on buyer-oriented criteria will aid in the development of the sales representative's role as a consultant to the client. The use of PPA will also help the buyer defend the purchasing decision that was made.     

6S优化检维修管理模式的实施

为提高设备检维修现场管理水平,中国石化南通石油分公司大岸桥石油机械厂钳工车间将6S现场管理理念导入钳工车间日常检维修管理中,通过对检维修现状和方式的分析,创新管理理念,制定有效的计划及措施并落到实处,使钳工现场检维修管理模式得到优化,提升了车间的管理水平。     

Breakeven Analysis with Inflationary Cost and Prices

A dynamic decision criterion for the sequential budgeting process is developed. Through the use of utility functions, this decision criterion models a decision maker's preferences for sequences of wealth positions generated by a set of investment opportunities relative to targeted wealth positions developed by the firm. The derivation of this criterion is related to cash flow analysis and the use of sequences of total wealth accumulations. Target-wealth utility functions are presented along with the motivation for their application to investment decision problems.