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Safety is today's one of the major issues within the health area all over the world. Among the factors that affect safety are the hazards originated by the utilization of medical equipment. Aiming at the reduction of the risks from such equipment, the clinical engineering groups have been developing programs for preventive maintenance and routines for safety inspections. Allied to these actions, the risk management techniques contribute to increase the efficiency of the risk control for medical equipment utilization. In this sense, a proposal of risk classification is presented here. [ABSTRACT FROM AUTHOR]

This paper develops an integrated neural-network- based decision support system for predictive maintenance of rotational equipment. The integrated system is platform-independent and is aimed at minimizing expected cost per unit operational time. The proposed system consists of three components. The first component develops a vibration-based degradation database through condition monitoring of rolling element bearings. In the second component, an artificial neural network model is developed to estimate the life percentile and failure times of roller bearings. This is then used to construct a marginal distribution. The third component consists of the construction of a cost matrix and probabilistic replacement model that optimizes the expected cost per unit time. Furthermore, the integrated system consists of a heuristic managerial decision rule for different scenarios of predictive and corrective cost compositions. Finally, the proposed system can be applied in various industries and different kinds of equipment that possess well-defined degradation characteristics. [ABSTRACT FROM AUTHOR]

Equipment failure can be expensive and potentially catastrophic. Unplanned production downtime, missed contract deadlines, costly machinery replacements, as well as safety problems, environmental concerns, and regulatory violations are all potential consequences of a maintenance program that fails to predict and monitor equipment problems. Phillip Mosher, CDPM Program Manager, Flowserve Corp. considers the ROI and the ability to minimize production, safety and regulatory problems. [Copyright &y& Elsevier]

An acoustic-emission technique is developed as a nonintrusive method and suitable maintenance-planning tool for inspecting the floors of storage tanks in order to find an optimum service-period duration. This paper deals with the methodologies and experiences gathered from field testing of above-ground storage tanks via the acoustic-emission technique conducted in refineries until now. The results of field testing conducted to date has led us to create a grading system for the purpose of maintenance of tank floors. The location of leak and corrosion sources that is based on the arrival-time difference in the acoustic-emission measurement is discussed, and findings gathered through source-location-placement algorithm and results are presented as a 2D map of tank-floor sources. [ABSTRACT FROM AUTHOR]

A brief comparative description of the ЛЮM1-OB and ЛЮM33-OB luminescent testing methods is given. A description regarding the main types of contaminations that, under conditions of production and repair of articles, must be removed from parts before luminescent inspection is given. The principles of preparing parts for luminescent inspection are described. Examples of part-cleaning techniques that comprise sequentially performed technical operations with allowance for the kinds of removed working media and contaminations are presented. [ABSTRACT FROM AUTHOR]

In some cases in haemodialysis blood access is established with a special type of central venous catheter (CVC), sometimes called a central dialysis catheter (CDC), instead of an AV fistula or graft. This central venous catheter tip is placed very close to the heart, increasing the probability of a leakage of electrical current passing through the heart. This may cause arrhythmia or ventricular fibrillation. This current is generally referred to as patient leakage current and has to be kept very low for patient safety. All staff involved in CVC treatments, nursing staff as well as technicians, should be aware of this particular risk to the patient. The purpose of this article is to discuss the background of the above-mentioned safety issue and suggest precautionary measures for minimising this risk. Precautions discussed include potential equalisation, use of separating transformers, periodic maintenance (normally performed by a service technician) and physical placement of the equipment used in the vicinity of the patient (normally the responsibility of the nursing staff). [ABSTRACT FROM AUTHOR]

Commonly used repair rate models for repairable systems in the reliability literature are renewal processes, generalised renewal processes or non-homogeneous Poisson processes. In addition to these models, geometric processes (GP) are studied occasionally. The GP, however, can only model systems with monotonously changing (increasing, decreasing or constant) failure intensities. This paper deals with the reliability modelling of failure processes for repairable systems where the failure intensity shows a bathtub-type non-monotonic behaviour. A new stochastic process, i.e. an extended Poisson process, is introduced in this paper. Reliability indices are presented, and the parameters of the new process are estimated. Experimental results on a data set demonstrate the validity of the new process. [ABSTRACT FROM AUTHOR]

This paper proposes an intelligent prognostics system (IPS) for semiconductor and TFT-LCD manufacturing. The IPS comprises several generic embedded devices (GED5) and remote clients. The GED can be easily embedded into various types of equipment to acquire equipment engineering data and meet the specification requirements of Interface A for supporting semiconductor industry equipment engineering capabilities. Furthermore, the GED has an open-standard application interface offering pluggable and customized intelligent applications. With this feature, the intelligent applications can be distributed and localized, releasing the factory network burden and enhancing equipment reliability and processing quality. This paper also develops two typical pluggable applications: the predictive maintenance scheme (PMS) for detecting equipment faults and the virtual metrology scheme (VMS) for conjecturing equipment-processing quality. Integrating the PMS into the IPS and the VMS into the IPS are, respectively, accomplished using the conveyor equipment and the sputtering equipment in a TFT-LCD factory. These two illustrative examples clearly demonstrate that IPS is versatile, configurable, and effective. [ABSTRACT FROM AUTHOR]

Purpose ? To provide maintenance engineering community with a model named ?Maintenance quality function deployment? (MQFD) for nourishing the synergy of quality function deployment (QFD) and total productive maintenance (TPM) and enhancing maintenance quality of products and equipment. Design/methodology/approach ? The principles of QFD and TPM were studied. MQFD model was designed by coupling these two principles. The practical implementation feasibility of MQFD model was checked in an automobile service station. Findings ? Both QFD and TPM are popular approaches and several benefits of implementing them have been reported worldwide. Yet the world has not nourished the synergic power of integrating them. The MQFD implementation study reported in this paper has revealed its practical validity. Research limitations/implications ? Since MQFD requires strategic decision making, the management commitment and support are required to test implement it. Since the case study was conducted in a public sector service station, this could not be achieved due to the requirement of following complex administrative procedures. However, the feasibility of obtaining customer voices from the practising community and translating them into technical languages has revealed the possibility of implementing MQFD in real time situations. Originality/value ? Both literature and manufacturing arenas were surveyed and found out that no model linking QFD and TPM has so far been brought out by theorists and practitioners. Hence the contribution of MQFD model is original. Since there are researches establishing the power of QFD and TPM, the essence of integrating them for attaining world class maintenance quality is of high value. [ABSTRACT FROM AUTHOR]

The field of medical devices is constantly growing and improving. New advancements impact many patients in need of life-saving devices. Therefore, it is important to know what new technologies are available and to have a thorough understanding of such devices. The left ventricular assist device (LVAD) is one such technology. The LVAD is an important device that continues to make significant advances, including LVADs now approved by the Food and Drug Administration for clinical use. This article is intended to educate the reader on the LVAD and its function. It includes a brief background followed by descriptions of the types of LVADs that are primarily used today. This is followed by a discussion of the different uses of the LVAD and a look at the LVAD's future. [ABSTRACT FROM AUTHOR]

The article presents an interview with Doctor Larry Fennigkoh bout his work with the Clinical Engineers Society. The issues of equipment inclusion and maintenance strategies have gained the interest of the public because the roles of clinical users and hospital administrators have evolved. The implementation of the medical equipment maintenance planning process has made the work of the clinical engineer easier.

Purpose ? The aim of the paper is to present the impact of human errors in maintenance as found in the literature in order for practitioners to be aware of their impact and develop actions to mitigate their effect. Design/methodology/approach ? The paper systematically categorizes the published literature and then analyzes and reviews it methodically. Findings ? Human error in maintenance is a pressing problem.Practical implications ? A maintenance person plays an important role in the reliability of equipment. It is also a well-known fact that a significantly large proportion of total human errors occur during the maintenance phase. Human error in maintenance is a subject which in the past has not been given the amount of attention that it deserves. This paper will be useful to people working in the area of maintenance engineering, as it presents a general review of literature published on maintenance errors in various sectors of industry. Originality/value ? The paper contains a comprehensive listing of publications on the field in question and their classification according to industry. The paper will be useful to researchers, maintenance professionals and others concerned with maintenance to understand the importance of human error in maintenance. [ABSTRACT FROM AUTHOR]

Purpose ? The aim of this research is to determine the optimal upgrade and preventive maintenance actions that minimize the total expected cost (maintenance costs+penalty costs). Design/methodology/approach ? The problem is a four-parameter optimization with two parameters being k-dimensional. The optimal solution is obtained by using a four-stage approach where at each stage a one-parameter optimization is solved. Findings ? Upgrading action is an extra option before the lease of used equipment, in addition to preventive maintenance action. Upgrading action makes equipment younger and preventive maintenance action lowers the ROCOF. Practical implications ? There is a growing trend towards leasing equipment rather than owning it. The lease contract contains penalties if the equipment fails often and repairs are done within reasonable time period. This implies that the lessor needs to look at optimal preventive maintenance strategies in the case of new equipment lease, and upgrade actions plus preventive maintenance in the case of used equipment lease. The paper deals with this topic and is of great significant to business involved with leasing equipment. Originality/value ? Nowadays many organizations are interested in leasing equipment and outsourcing maintenance. The model in this paper addresses the preventive maintenance problem for leased equipment. It provides an approach to dealing with this problem. [ABSTRACT FROM AUTHOR]

This paper explores the impact of imperfect repair on the availability of repairable equipment. Kijima's first virtual age model is used to describe the imperfect repair process. Due to the complexity of the underlying assumptions of this model, we are unable to derive a closed-form equation for availability. Therefore, simulation modeling & analysis are used to evaluate equipment availability. Based on initial availability plots, a generic availability function is proposed. A 2³ factorial experiment is performed to evaluate the accuracy of this model. The maximum absolute error between the simulation output, and the corresponding values of the availability function is 3.82%. This indicates that our proposed function provides a reasonable approximation of equipment availability, which simplifies meaningful analysis for the unit. Therefore, a method is defined for determining optimum equipment replacement intervals based on average cost. Next, meta-models are developed to convert equipment reliability & maintainability parameters into the coefficients of the availability model. We expand on our initial experiment using a circumscribed central composite experimental design. We evaluate the accuracy of the meta-models for the 15 experiments & 50 random experiments within the design space. For the 50 new experiments, we compare the replacement policy obtained from analysis of the meta-model to the policy obtained directly from the simulation output. The average increase in cost resulting from the sub-optimal replacement policy is only 0.10%. Therefore, we conclude that the meta-models are robust, and provide good estimates of the parameters of our proposed availability function. By doing this, we eliminate the need to perform simulation to obtain the parameters of the availability model. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a study on the so called vertical displacement events (VDEs) in elongated and diverted tokamak plasmas. The study is carried out using two numerical codes: DINA for the two-dimension (2D) and M3D for the three-dimension (3D) simulations, respectively. The DINA simulations are compared with the experimental data taken from some ASDEX-U disruptive events. A realistic (ITER relevant) equilibrium is considered for the M3D simulations. [Copyright &y& Elsevier]

Abstract: One of the key maintenance operations for the ITER tokamak is the remote replacement of its divertor system. The components making up this system are expected to be activated to a level of several hundred gyrations per hour and contaminated with hazardous and/or activated dust (beryllium, carbon, tungsten) and tritium. A suite of specialized remote handling (RH) equipment is, therefore, necessary to facilitate divertor exchange. This paper describes the ITER divertor maintenance approach together with recent European efforts towards the design and development of the associated remote handling equipment and procedures. [Copyright &y& Elsevier]

Abstract: This paper deals with effective forecasting methods for typically lumpy demand for aircraft spare parts, and analyzes the behavior of forecasting techniques when dealing with lumpy demand. Twenty forecasting techniques are considered and tested and historical data from Alitalia are used to analyze and compare their performance. The results demonstrate that item lumpiness is the dominant parameter and show that demand forecasting for lumpy items is a complex problem; results from previous studies are not very accurate. The best approaches are found to be weighted moving averages, the Croston method, and exponentially weighted moving average models. [Copyright &y& Elsevier]

The article presents information on effective equipment management, and indicates the emergence of a new period known the "post-maintenance era." Machinery is considered as a necessity in several industries instead of an alternative. After the success of reliability theory in Japan, a large number of firms started to apply statistics to equipment management. Then the trend was followed by Total Productive Management. Computer technologies were applied in large numbers to enhance maintenance activities. As a result of the environmental changes in the semiconductor industry, the transition from maintenance era to the post-maintenance era occurred.

The traditional model of optimal reactive power dispatch (ORPD) for power systems is based on the principle of income maximization, which aims at minimizing active power loss of the whole networks. However, such a model may bring on excessive operations of device-control devices in real-time application. To realize reactive power dispatch, power utilities should increase equipment investment and added manpower for operation and maintenance. On the other hand, the operation and maintenance. On the other hand, the operations would augment the fault probability of power systems. Therefore, the costs of adjusting the control devices (CACDs) are investigated, and a novel mathematical model of ORPD is presented in this paper, whose objective function is to minimize the energy loss at the current time interval and the CACD. A simulation test is presented to demonstrate that the proposed model reflects the principle of profit maximization and describes the ORPD problem with time-varying loads appropriately since it can decrease active power loss and avoid excessive controls simultaneously. [ABSTRACT FROM AUTHOR]

Abstract: Recent developments in the condition monitoring and asset management market have led to the commercialisation of online vibration-monitoring systems. These systems are primarily utilised to monitor large mineral mining equipment such as draglines, continuous miners and hydraulic shovels. Online monitoring systems make diagnostic information continuously available for asset management, production outsourcing and maintenance alliances with equipment manufacturers. However, most online vibration-monitoring systems are based on conventional vibration-monitoring technologies, which are prone to giving false equipment deterioration warnings on gears that operate under fluctuating load conditions. A simplified mathematical model of a gear system was developed to illustrate the feasibility of monitoring the instantaneous angular speed (IAS) as a means of monitoring the condition of gears that are subjected to fluctuating load conditions. A distinction is made between cyclic stationary load modulation and non-cyclic stationary load modulation. It is shown that rotation domain averaging will suppress the modulation caused by non-cyclic stationary load conditions but will not suppress the modulation caused by cyclic stationary load conditions. An experimental investigation on a test rig indicated that the IAS of a gear shaft could be monitored with a conventional shaft encoder to indicate a deteriorating gear fault condition. [Copyright &y& Elsevier]

Abstract: In the classical p-center problem there is a set V of points (customers) in some metric space, and the objective is to locate p centers (servers), minimizing the maximum distance between a customer and his respective nearest server. In this paper we consider an extension, where each customer is associated with a set of existing depots or distribution stations he can use. The service of a customer consists of the travel of a server to some permissible depot, loading of some package (e.g., a spare part) at the depot, and the delivery of the package to the customer. This model is called the customer one-way problem. In the round-trip version of the problem, the service also includes the travel from the customer to the home base of the server. In both problems the customer cost of the service is a linear function of the distance travelled by the server. The objective is to locate p servers, minimizing the maximum customer cost (weighted distance travelled by the respective server). Since the classical p-center problem is NP-hard, so are the one-way and the round-trip models we study. We present efficient constant factor approximation algorithms for these problems on general networks. Turning to special networks, we prove that the one-way problem is strongly NP-hard even on path networks. We then present polynomial time algorithms for the round-trip problem on general tree networks. We also discuss the single center case, and provide polynomial time algorithms for general networks, tree networks and planar Euclidean and rectilinear metric spaces. [Copyright &y& Elsevier]

Abstract Shortening a time gap between oil sampling and its analysis as well as a rapid and correct interpretation of dissolved gas analysis (DGA) results are crucial for effective screening of faulty transformers in predictive-oriented equipment maintenance. Introductory DGA performed quickly by means of a developed portable analyzer, fitted with electrochemical gas sensors, can supplement classical chromatography-based DGA contributing to a correct and rapid transformer fault interpretation. Examples of unusual data mining for sensor-based DGA are also presented. [ABSTRACT FROM AUTHOR]

An autonomous control system for Mössbauer spectrometry based on two modules has been designed and built. The first module operates as a multichannel analyzer for the acquisition and storage of spectra, and the second one is a driver unit which controls and supplies the power for the velocity transducer. A microcontroller executes the digital control algorithm for the velocity transducer motion and manages the data acquisition and storage tasks. The user can monitor the system from an external PC through the serial port. A graphic interface made with the LabVIEW software allows the user to adjust digitally the control parameters for the velocity transducer motion, the channels number, to visualize as well as save spectra in a file. The microcontroller can be reprogrammed from the PC through the same serial port without intervention of a universal programmer, which allows the user to make proper software for different applications of the system. The system has been tested for linearity with several standard absorbers yielding satisfactory results. The low cost of its design, construction and maintenance make this equipment to be an attractive choice when assembling a Mössbauer spectrometer. [ABSTRACT FROM AUTHOR]

The article presents information about conferences, which are scheduled to be held in coming months. A conference "Track Quality 2005" to be held on 8 and 9 February 2005 at the Hesperia London Victoria will focus exclusively on the engineering and technology aspects of track quality, from maintenance and renewal to track diagnostics and condition monitoring to management of the maintenance equipment. "International Conference: Design and Operation for Abnormal Conditions" will be held on 26 and 27th January 2005 at the Royal Institution of Naval Architects, London, Great Britain.

Remarkable improvements have occurred recently in the maintenance management of physical assets and productive systems, so that less wastages of energy and resources occur. The requirement for optimal preventive maintenance, using, for instance, just-in-time (JIT) and total quality-management (TQM) techniques, has given rise to what has been called the total productive-maintenance (TPM) approach. This study explores the ways in which Nigerian manufacturing industries can implement TPM as a strategy and culture for improving its performance and suggests self-auditing and bench-marking as desirable prerequisites before TPM implementation. [Copyright &y& Elsevier]

Abstract: Early detection of process disturbances and prediction of malfunctions in process equipment improve the safety of the process, minimize the time and resources needed for maintenance, and increase the uniform quality of the products. The objective of online-monitoring is to trace the state of the process and the condition of process equipment in real-time, and to detect faults as early as possible. In this article the different properties of the online-monitoring methods applied in the process industries are first reviewed. A description of the systematic development of the online-monitoring system for an industrial dearomatization process, specifically for flash point and distillation curve analysers, is then presented. Finally, the results of offline and online tests of the monitoring system using real industrial data from the Fortum Naantali Refinery in Finland, are described and discussed. The developed online-monitoring application was successful in real-time process monitoring and it fulfilled the industrial requirements.PACS: 07.05.Mh; 07.05.Tp; 83.85.Ns [Copyright &y& Elsevier]

Equipment, be it sophisticated or basic in operation and design, depending on its usage, will inevitably malfunction and breakdown. Within any organisation where manufacture is the primary activity, it is crucial that procedures exist for equipment maintenance. Not only does equipment maintenance need to be planned for, the possibility and probability of breakdowns and disruption to operations must also be considered when planning and scheduling production. This paper examines the basis of various maintenance management strategies used to date in international manufacturing. These strategies assist the maintenance function and enable the process of maintenance to be optimised. Special attention is given to Computerised Maintenance Management Systems (CMMSs), how this particular strategy was successfully implemented in a medium sized Irish textile manufacturing company. [Copyright &y& Elsevier]

In many environments, product yield is heavily influenced by equipment condition. Despite this fact, previous research has either focused on the issue of maintenance, ignoring the effect of equipment condition on yield, or has focused on the issue of production, omitting the possibility of actively changing the machine state. We formulate a Markov decision process model of a single-stage production system in which demand is random. The product yield has a binomial distribution that depends on the equipment condition, which deteriorates over time. The objective is to choose simultaneously the equipment maintenance schedule as well as the quantity to produce in a way that minimizes the sum of expected production, backorder, and holding costs. After proving some results about the structural properties of the optimal policy, numerical problems are used to compare this method to the typical approach of solving the maintenance and production problems sequentially. The results show that the simultaneous solution provides substantial gains over the sequential approach. In the cases studied, the proposed method resulted in an average cost savings of approximately 18%. [ABSTRACT FROM AUTHOR]

Industrial manufacturers strive to maximize uptime of plant operations and processes. However, downtime can be a valuable asset and present many opportunities to address those critical maintenance items that can impact reliability. Since motors and associated driven equipment comprise almost 90% of the process loads, identifying and correcting these mechanical and electrical maintenance problems will reduce unplanned production shutdowns and significantly increase business profits. This paper explores the various protection technologies available to the plant and design engineer for implementation of a cost effective and reliability centered motor management program. [ABSTRACT FROM AUTHOR]

Reports on the move of Kropotkinski Machine-Building Plant, a leading machine-building enterprise, in developing equipment for construction and maintenance of oil and gas pipelines. Movement of the machine in the guides of the trolley hangers; Prevention of shaking the machine in the center-line plane of the pipe; Insulation of pipeline along a helical line with layers of adhesive polymer tape and protective wrapper.

Airline operators and maintenance organizations were queried regarding their maintenance and inventory procedures. Of 175 respondents, 152 were using the reorder point system, and the remainder the material requirements planning (MRP) system. The survey was intended to examine the experience of companies using MRP. It indicates that the aircraft parts industry takes this system seriously. However, it is more difficult to implement in the aircraft maintenance environment than in a commercial environment, where the need for spare parts is unpredictable. But if the obstacles are understood and a sound plan is realised by good management, MRP can be successfully implemented, with substantial benefits. [Copyright &y& Elsevier]

Using recovered parts from discarded electrical and electronic equipment as spare parts within closed-loop supply chains is promising, especially during the final service phase, when the original product is no longer produced and the sources of new parts are limited. Controlling those closed-loop supply chains and to decide when to acquire discarded equipment, when to recover used parts, and when to produce new parts is challenging. To cope with this problem, we developed a generic system dynamics model that provides a test for various proposed policies to control closed-loop supply chains with parts recovery and spare parts supply. [ABSTRACT FROM AUTHOR]

With the advent of the resources' boom in the late 1960s, most of the larger scale resources projects in Australasia were commissioned on an 'owner-mining' basis, where the mine owners owned and operated the primary mining equipment. Then, in the 1980s with the arrival of the gold mining boom in Western Australia and elsewhere, a change occurred - most of the mining activities were carried out on a contract mining basis. Over recent years, however, there has been a marked trend amongst larger Australasian open pit mining operations back towards owner-controlled and operated mining operations. The reasons for this are many and are addressed in the paper, but centre on the concept of the owner being prepared to assume more of the mining risk in exchange for the advantage of not having to pay a contractor's profit margin. Where mining contracts are entered into, the older 'schedule of rates' format is being replaced with less adversarial and more entrepreneurial contract alternatives involving operating cost and risk sharing in a spirit of 'fair dealing'. Leasing and maintenance issues have also been influenced in recent years by the advent of more flexible contract arrangements with equipment suppliers. Group purchasing has also had some influence for project operators. For many mine owners, the optimal risk management profile involves a practical off-setting of the assumption of mining risk on the one hand, against the removal of litigation risk and potentially reduced operating costs on the other. Potential pitfalls may arise where equipment size and type requirements vary with time or where manpower management, mining flexibility, job skills or safety exposure factors are relevant. These issues are commented on in the context of some well-known examples, and an update is provided on contract mining versus owner operation in large scale Australasian open pit mining generally. [ABSTRACT FROM AUTHOR]

Provides information on the U.S. Air Force Aircraft/Missile Technical Coordination Program. Formation of the first Technical Coordination Group (TCG) by the U.S. Air Force; Benefits of TCG membership; Information on active TCG.

Following a brief historical overview of maintenance practice, the principles that govern tribological phenomena are summarized in terms of the issues involved in the upkeep and care of operating machinery. Condition-based and proactive maintenance strategies are identified in order to permit examination of the key tribological factors involved and what steps are being taken to assist in the implementation of good practices. Some of the issues to be faced when maintaining equipment in the aerospace, steel and pharmaceutical industries are highlighted as a basis for indicating ways in which the tribologist can further contribute to improving maintenance practice. [ABSTRACT FROM AUTHOR]

Spare parts optimisation requires an integrated approach that starts with the removal of factors that create noise: bad coding, resulting in parts proliferation; lack of classification and thus of focus; poor network practices (uncoupled warehouses, poor relation with key suppliers); and poor data integrity (non-centralised, non-real time data). Emphasis is also placed on improving forecasts and the application of multi-echelon inventory models for repairable items. The METRIC model is then applied to a hypothetical and two real cases, an underground system and a mobile telephone company in Venezuela. [ABSTRACT FROM AUTHOR]

Risk is inherent in every construction project, especially complex projects like high rise buildings. It is helpful to understand the significant risks in order to anticipate their possible negative effects on projects. This research identifies, ranks and categorizes high potential risks in high rise building projects in Jakarta. Questionnaire surveys and interviews were conducted on engineers from contracting firms in the city. The result shows that risks related to management and design are the most significant in high rise construction projects. It is also shown that client interference should be avoided or reduced in tandem with good communication and teamwork between contractors and consultants to minimize defects. Contractors also need to give attention to the maintenance of equipment in order to sustain high productivity levels. [ABSTRACT FROM AUTHOR]

The accurate estimation of equipment utilization is very important in capital-intensive industry since the identification and analysis of hidden time losses are initiated from these estimates. In this paper, a new loss classification scheme for computing the overall equipment effectiveness (OEE) is presented for capital-intensive industry. Based on the presented loss classification scheme, a new interpretation for OEE including state analysis, relative loss analysis, lost unit analysis and product unit analysis is attempted. Presents a methodology for constructing a data collection system and developing the total productivity improvement visibility system to implement the proposed OEE and related analyses. [ABSTRACT FROM AUTHOR]

The article focuses on the development of a Markov decision process model that simultaneously determines maintenance and production schedules for a multiple-product,single-machine production system, accounting for the fact that equipment condition can affect the yield of different product types differently. In the semiconductor industry, it is common for a production facility to produce many products of varying types and technological complexities. Specifically, the problem of scheduling production and maintenance of a multiple-product manufacturing system with a single, deteriorating machine was modeled as a Markov decision process. The state of the machine, which changes stochastically over time, affects the yield of different product types differently. The decision maker must determine whether to clean the machine or keep producing, and, if production is picked, which product type to produce. The problem was motivated by an application in the semiconductor industry. The results suggest that the improvement provided by the combined method increases as the diversity of the products increases and that most of the improvement is due to changing the production schedule rather than the maintenance schedule. In the problems studied. the reward from the combined method was an average of more than 25 percent greater than the reward from the traditional method.

In this paper, we study the operational availability of a complex technical system consisting of several components. The components are subject to breakdowns, and hence for each component a limited number of spare parts are held in stock. If a system's component fails and it can not be replaced immediately, due to a lack of spares, the system becomes unavailable until a new component is installed. Failed components are disposed of and hence, to keep the spare parts stock at an appropriate level, new components have to be purchased. We assume that only a limited annual budget is available for procurement, while any further procurement requires a considerable lead time. We investigate at an aggregate level what budgets are needed to attain a target availability level for the system. In addition, we develop various operational strategics for spending the annual budget during each year. Numerical results indicate that the so-called Balance Focussed strategy provides the best results in terms of system availability as a function of time. [ABSTRACT FROM AUTHOR]

In this paper, we model the situation where operator maintenance activities improve the failure process of equipment. We analyze the business decision to reduce both the mean and variance of the production cycle time and the overall inventory level through an investment in planned autonomous maintenance. We answer: (i) when do optimal autonomous maintenance decisions most improve inventory levels?; and (ii) how do capacity restrictions, equipment characteristics the maintenance response function, and product characteristics impact the autonomous maintenance investment decision? Extensive numerical analyses are performed to develop an approximation to the optimal response for both inventory and autonomous maintenance investments over a wide range of problem parameters. Our solutions provide guidelines on how much time should be invested in autonomous maintenance activities and describe when companies can most benefit from autonomous maintenance programs that increase equipment reliability. We determine the investment in autonomous maintenance activities as a function of available capacity, equipment reliability and demand characteristics. [ABSTRACT FROM AUTHOR]

The article attempts to build theory on the relationship between skill levels and advanced manufacturing technologies (AMT). AMT has been posited to require higher skills than previous technologies. The basis for this proposition is the complex nature of the technology. This research sheds doubt on the high skill assumption. Not only is there no evidence of a linear or simple curvilinear relationship between skills and performance, but some of the highest performing companies in the sample are using preparation times of less than 10 weeks. These companies are using both Computer Numerically Controlled equipment and flexible manufacturing systems with employees whose training would not prepare them for many tasks. Such tasks include working in semi-autonomous teams, performing their own maintenance, programming their own equipment and being able and willing to learn and respond to different customer requirements. Therefore the key conclusion of this research is that companies need not have highly skilled employees to have high levels of AMT performance.

Aircraft maintenance is undergoing a paradigm shift towards predictive maintenance, where the use of sensor data and Remaining-Useful-Life prognostics are central. This paper proposes an integrated approach for predictive aircraft maintenance planning for multiple multi-component systems, where the components are repairables. First, model-based Remaining-Useful-Life prognostics are developed. These prognostics are updated over time, as more sensor data become available. Then, a rolling horizon integer linear program is developed for the maintenance planning of multiple multi-component systems. This model integrates the Remaining-Useful-Life prognostics with the management of a limited stock of spare repairable components. The maintenance of the multiple systems is linked through the availability of spare components and shared maintenance time slots. Our approach is illustrated for a fleet of aircraft, each equipped with a Cooling System consisting of four Cooling Units. For an aircraft to be operational, a minimum of two Cooling Units out of the four need to be operational. The maintenance planning results show that our integrated approach reduces the costs with maintenance by 48% relative to a corrective maintenance strategy and by 30% relative to a preventive maintenance strategy. Moreover, using predictive maintenance, components are replaced in anticipation of failure without wasting their useful life. In general, our approach provides a roadmap from Remaining-Useful-Life prognostics to maintenance planning for multiple multi-component systems of repairables with a limited stock of spares. • Model-based Remaining-Useful-Life prognostics for aircraft Cooling Units are developed. • A predictive maintenance planning model is developed for multiple multi-component systems. • The planning model integrates RUL prognostics with the management of a limited stock of repairable spare components. • A case study on the maintenance of repairable aircraft Cooling Units is conducted. • Predictive maintenance planning is shown to outperform corrective and preventive maintenance. [ABSTRACT FROM AUTHOR]