Effect Of Preventive Maintenance Research Articles

Stochastic Analysis of Two Non-identical Unit Parallel System Incorporating Waiting Time and Preventive Maintenance

The reliability of two non-identical unit’s parallel system with two kinds of failures common cause failure and partial failures is inspected. Moreover, the preventive maintenance and waiting time to repair, a significant aspect of reliability analysis, has also been incorporated. The proposed system is assumed to a function properly if at least one of the unit is in operate mode. The system goes for preventive maintenance at random apaches. Supplementary variable technique and Laplace transform have used for solution. Our results are compared with the previous results to observe the effect of preventive maintenance and failure rates on system performance.

Targeted Preventive Maintenance of Pharmaceutical Equipment

To study effective management mode for preventive maintenance of equipment in pharmaceutical enterprises. Different pharmaceutical equipment has different importance in the producing process, so maintenance to each equipment should be different. A targeted maintenance reqiures to classify equipment and its components. To this aim, with help of assessment tools such as System Impact Assessment(SIA), Component Criticality Assessment(CCA) and deision-making grip, the specific targeted maintenance plan can be made and then implement it. Check the effect and feed back the problems. According to assess result of SIA & CCA, and deision-making grip, Pharmaceutical equipment can be classified into key equipment, important equipment and insignificant equipment. Components of equipment can be divided into two levels, critical and non-critical. For critical components of key equipment, comprehensive maintenance is needed. Maintenance of non-critical parts of key equipment and critical parts of important equipment should be paid great attention to. As for non-critical parts of important equipment and insignificant equipment, daily maintenance is enough. Such maintenance plan makes a distinction between the important equipment and the lesser ones. Through targeted management, preventive maintenance effect can be improved.

Мероприятия по устранению негативных медико-социальных факторов риска, влияющих на частоту родоразрешений путем операции кесарево сечение

This article presents data on the development and justification of measures to eliminate (weaken) negative medical and social risk factors that have a significant effect on the rate of delivery by cesarean section. For this purpose, the degree of influence of medical and social risk factors was determined using the prognostic model developed by us to predict the proportion of these factors' influence on delivery by cesarean section. In order to study the effectiveness of preventive maintenance of delivery by cesarean section according to the measures developed by us, an organizational experiment was conducted. This organizational experiment was conducted in 2015-2016. in women's consultations, medical organizations in Kazan. The measures we developed for the prevention of delivery through cesarean section have made it possible to obtain a noticeable preventive effect in reducing the frequency of this operation and increase the effectiveness of the obstetrician-gynecologists work. Thus, according to our study, elimination of 49.6% of negative medical and social risk factors among pregnant women allowed, in comparison with the control group, to reduce the rate of delivery of operations by cesarean section by 56.8%, and among women planning pregnancy the frequency of delivery by cesarean operation The cross section decreased by 60.5%.

Establishment of an Evaluation Model for Asphalt Pavement Preventive Maintenance Based on Improved EW-AHP

The evaluation methods for asphalt pavement preventive maintenance both local and abroad are investigated in this study. A comprehensive evaluation model that combines the evaluation index of pavement and material performance in domestic technical specifications and that considers the lack of weight allocation method for evaluation indices is proposed for the preventive maintenance of asphalt pavement. On the basis of the combination of practical engineering experiences, the expert scoring method, and experimental testing data, the model utilizes a new method, i.e., the improved entropy weight-analytic hierarchy process, to calculate the comprehensive weight coefficients of various evaluation indices and to evaluate the effect of preventive maintenance. The preventive maintenance engineering of highway asphalt pavement in Zhangjiakou is used as an example. Results show that the model is feasible. Moreover, the results can provide technical support for the application of preventive maintenance measures to asphalt pavement.

THE EFFECT OF IMPLEMENTATION PREVENTIVE MAINTENANCE SYSTEM AND THE VALUES OF AVAILABILITY, PERFORMANCE AND QUALITY TOWARDS OVERALL EQUIPMENT EFFECTIVENESS (Case Study in PT. Astra Honda Motor)

The background of this research refers to many companies that cannot identify about the system effect and overall equipment effectiveness (OEE) values, and cannot implement the right system continuously. So that, this research is to investigate some factors that influence the OEE values. The objective of this research were to investigate the effects of preventive maintenance to OEE and to decide whether of availability, performance, quality that most contribute to OEE values at PT. Astra Honda Motor. The design of this research applies case study to examine all hypothesis in this study. The methods used in this study was simple and multiple regression between independent variables and dependent variable. Data analysis used in this research were collected from preventive maintenance activity data and machining crank case production data. There were 91 average data of preventive maintenance activity and usable for analyzed by simple regression and 578 average data of machining crank case production completed and usable for analyzed by multiple regression. The result of research indicated that the first, preventive maintenance has no significant impact to OEE values. The second, availability give more contribution to OEE values than performance and quality.

예방적 유지관리를 통한 교량의 생애주기비용 절감 효과 분석

본 논문은 교량의 예방적 유지관리 효과를 생애주기비용 절감 측면에서 분석 하였다. 예방적 유지관리는 현재 실시되고 있는 대응적 유지관리 전략과 대비 되는 유지관리 전략으로 교량의 열화지연을 통해 궁극적으로는 교량의 사용수명을 연장 시키며 생애주기비용을 절감시키는 유지관리 전략이다. 이러한 예방적 유지관리 효과를 분석하기 위해 교량의 공용연수에 따른 건전도 점수 변화 모델과 FHWA 자료를 바탕으로 한 국내 고속도로 교량의 건전도 점수에 따른 보수 보강 비용 모델을 제시 하였다. 제시한 복수의 모델과 국내외 참고 문헌을 바탕으로 제안된 예방적 유지관리 항목(청소와 도장)의 비용과 주기를 활용하여 사용수명 100년까지의 표준교량(<TEX>$1,730m^2$</TEX>/교량) 당 생애주기 비용과 향후 20년간의 고속도로 총 유지관리 비용을 산정 하였다. 분석 결과 100년간 예방적 유지관리 활동으로 인해 교량 당 5억원의 절감효과를 볼 수 있으며 현재 예방적 유지관리 활동을 실시할 경우 20년 후(2035년)에는 총 1,837억원, 즉 연간 약 92억원의 비용 절감효과를 볼 수 있는 것으로 분석 되었다. The paper aims at evaluating effects of preventive maintenance on life cycle cost(LCC) reduction of bridges. The preventive maintenance activities capable to delay bridge deteriorations can reduce overall maintenance costs and extend service life of a bridge by regularly providing maintenance activities and avoiding larger maintenance(repairs or rehabilitations) costs. Couple of prediction models were proposed in order to calculate LCC of a typical bridge: a health score model and repair rehabilitation cost model. In addition, the maintenance activities such as wash and painting were also suggested in order to consider effects of preventive maintenance in the analysis based on literature reviews. According to analysis results, new maintenance strategy(reactive maintenance + preventive maintenance) can save \0.5 billion per bridge for future life-cycle costs over 100 year analysis or \184 billion for entire HBMS(Highway Bridge Management System) inventory over 20 years. Small investments for preventive maintenance in improved bridge management can have a very significant return when considering the large bridge inventory.

Modeling Failure Process and Quantifying the Effects of Multiple Types of Preventive Maintenance for a Repairable System

In this paper, we consider a repairable system whose failures follow a non‐homogenous Poisson process with the power law intensity function. The system is subject to corrective and multiple types of preventive maintenance. A corrective maintenance has a minimal effect on the system; however, a preventive maintenance may reduce the system's age. We assume the effects of different preventive maintenance on the system are not identical and derive the likelihood function to estimate the parameters of the failure process as well as the effects of preventive maintenance. Moreover, we derive the conditional reliability and the expected number of failures between two consecutive preventive maintenance types. The proposed methods are applied to a real case study of four trucks used in a mining site in Canada. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Studies the Reliability and Availability Characteristics of Two Different System under Preventive Maintenance

The research studies the availability and reliability to two systems which different due to the effect of preventive maintenance (PM), a two system analyses a two state with two type failure. The rate of failure is exponential distribution but the rate of repair is general distribution. The system resolved by supplementary technique and Laplace transforms depend on Complex imagine roots. Several measures of availability and (MTTF) of system are obtained. we analysis graphically to watch the impress of several system parameters in mean time failure and availability.

Development of a monitoring scheme for preventive maintenance of the cement machinery.

It was underscored that the optimization of policies of preventive maintenance has become a subject of much research. This article proposes a new optimal policy of preventive maintenance for the roller shaft system. It is divided into two main sections. The first proposes a new design of the shaft where the effect of preventive maintenance is integrated, and the second is developing a new control technique adapted to the new design. In this regard, we are interested in the shaft of rollers of the rotary kilns of cement. We have noted the stresses imposed to the axis of the roller. These constraints that have stemmed from the contact between tire and its support rollers. Currently the ultrasonic inspection method of the solid shaft in this situation poses disadvantages, for example, the obligation to stop the rotary Kiln and the difficulty of detecting and sizing defects (fatigue cracks). We propose in this study another approach, we recommend opting for a hollow shaft instead of a solid shaft with a minimum diameter that allows the control system to enter hollow shaft to show for inspection purposes. This will allow preventive control, in operation by the non-destructive technique of ultrasound. The analysis shows the different results of comparison between the axis of full and hollow cylinders, having the same dimensions and the same material and ultimately the most interesting is the same operation.

Improving reliability of repairable systems using preventive maintenance and time-between-failures monitoring

The purpose of this article is to investigate how to assess the rate of occurrence of failure (ROCOF) of a multi-component repairable system and improve its reliability. A procedure was developed and tested on closed-circuit television dome cameras operated in an airport in the United Arab Emirates. Optimum replacement times for critical components were calculated, and then a practical preventive maintenance schema was suggested to reduce the overall cost. Finally, a control chart was developed to monitor the time between failures (TBFs) on the basis of the calculated ROCOF. The results of the case study show that optimising the maintenance renewal intervals generated a saving of approximately 77% in maintenance costs, reduced the ROCOF by approximately 94%, and increased the level of planned maintenance by approximately 97%. Furthermore, monitoring the TBFs of repairable systems could detect changes that might lead to failures over time, thus improving the reliability and ensuring the effectiveness of preventive maintenance. [Received 12 April 2015; Revised 27 December 2015; Revised 3 March 2016; Accepted 18 March 2016]

Effectiveness Analyses of Flexible Pavement Preventive Maintenance Treatments with LTPP SPS-3 Experiment Data

AbstractThe present study analyzes the effectiveness of preventive maintenance (PM) treatments of flexible pavements utilizing data obtained from the specific pavement study 3 (SPS-3) of the long-term pavement performance (LTPP) program online database. The PM treatments included in this study are thin hot mix asphalt (HMA) overlay, chip seal, slurry seal, and crack seal. International roughness index (IRI), rutting, fatigue cracking, longitudinal cracking, and transverse cracking were selected as indicators of pavement performance. Initial roughness change, long-term roughness change, and weighted distresses are used as measures of effectiveness. The logistic regression model is employed to investigate the influence of pretreatment roughness condition, pretreatment surface condition, and several other factors on the performance of PM treatments. Results from this study indicate that only thin overlay and chip seal are effective in retarding fatigue cracking. Thin overlay was also the only treatment effec...

Control system modeling of stock management for civil infrastructure

Management of infrastructure stock is essential in sustainability of society, and its analysis and optimization are studied in the light of control system modeling in this paper. At the first part of the paper, cost of stock management is analyzed based on macroscopic statistics on infrastructure stock and economical growth. Stock management burden relative to economy is observed to become larger at low economic growth periods in developed economies. Then, control system modeling of stock management is introduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulated and compared with existing time history statistics. Assuming steady state conditions, applicability of the model to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventive and corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed in terms of preventive and corrective maintenance actions, is derived based on estimated parameter values for corrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when target deteriorated stock level is lower.

Effect of preventive maintenance on supply chains with one producer and multiple newsvendors

It is well-known that the production decisions are influenced by the state of the production process. Therefore, the process must be maintained in top operating conditions through adequate maintenance programmes. A supply chain with one producer and multiple newsvendors is considered in this article. The production process in this supply chain is assumed to be imperfect in a sense that it may fail at any point in time during the production run. In the supply chain under consideration, if the production process fails, failure maintenance (FM) is conducted which brings the process to as-bad-as-old conditions. Regardless of the number of failures that have already occurred and after a fixed interval of time, the process undergoes preventive maintenance (PM) which brings the process to as-good-as-new conditions. The objective of the model is to determine the optimal production and maintenance schedules that maximise expected total profit of the supply chain. The proposed model is general in a sense that it is not specific to certain sector or supply chain. A closed form solution is obtained and numerical analysis is conducted on key parameters of the model. Moreover, the model is solved using diverse input data; the results show similar trends in all cases.

Boroscopy Application in Assurance of Technological Equipment Operational Capability

This paper is focused on an emphasis of the preventive maintenance effect on reliable and safe operation of technological equipment, in view of technical diagnostics. Problems of the boroscopy as a diagnostics method providing fast information acquiring of inner parts of technological equipment turbomachinery RB211 DLE assembled in combined cycle gas turbine (CCGT) in selected company [. Observations were focused on high pressure axial compressor, being the main part of monitored technological system. From quality point of view the paper provides new perspective of internal inspection of technological equipment covering possible damages locating and qualifying of qualitative characteristics of equipment inner parts. The problems solved were based on particular practice demands and it reflects state-of-art in concerned scientific field [.

Failure rate modelling of electric distribution overhead lines considering preventive maintenance

The electric distribution overhead lines are large-scale complex repairable systems that consist of numerous components. To obtain an acceptable level of reliability in overhead lines, an asset management strategy seems to be necessary. An asset management-based maintenance framework is introduced for overhead lines. Based on the proposed framework, a relevant failure rate model is developed, which is able to show the effect of preventive maintenance according to expending cost and other affecting factors. The application procedure of the proposed model is also discussed in overhead line maintenance planning. Five-year historical data of nine feeders are used to assess the proposed maintenance schedule in comparison to utility predefined one.

Failure analysis of medical linear accelerator with reliability analyses

We analyzed a number of cases about the Linac troubles in our hospital and have examined the effect of preventive maintenance with Weibull analysis and exponential distribution from April 2001 to March 2012. The total failure by irradiation disabled was 1, 192. (1) Medical linear accelerator (MLC) system was 24.0%, (2) radiation dosimetry system 13.1%, and the (3) cooling-water system was 26.5%. It accounts for 63.6% of the total number of failures. Each parameter value m, which means the shape parameter, and the failure period expectancy of parts μ were (1) 1.21, 1.46/3.9, 3.8 years. 3.7, 3.6 years. (2) 2.84, 1.59/6.6, 4.3 years. 6.7, 5.9 years. (3) 5.12, 4.16/6.1, 8.5 years. 6.1, 8.5 years. Each shape parameter was m>1. It is believed that they are in the worn-out failure period. To prevent failure, MLC performance should be overhauled once every 3 years and a cooling unit should be overhauled once every 7 years. Preventive maintenance is useful in assessing the failure of radiation therapy equipment. In a radiation dosimetry part, you can make a preemptive move before the failure by changing the monitor's dosimeter board with a new part from the repairs stockpiled every 6 months for maintenance.

A Comparative Analysis of Three Unit Redundant Systems with Three Types of Failures

In this paper, three probabilistic models for a redundant system with three identical units have been developed to analyze and compare some reliability characteristics. Model II and model III are special cases of model I. In each model, the system is under three types of failures and attended by one repairman. Model I is under preventive maintenance before failure, while model II and III are analyzed without preventive maintenance, and in addition model III is viewed as linear consecutive 2-out-of-3. The objective is to see the effect of preventive maintenance and system design of 2-out-of-3. Mean time to system failure, availability, busy period and profit function for the three models are analyzed using Kolmogorov’s forward equations method. Furthermore, we compare these reliability characteristics for the three models and found that model I is more reliable and efficient than the remaining models.

Differential Importance Measure for Components Subjected to Aging Phenomena

The paper refers to the evaluation of the unavailability of systems made by repairable binary independent components subjected to aging phenomena. Exponential, exponential-linear, and Weibull distributions are assumed for the components failure times. We assume that components failure rate increases only slightly during the maintenance period, but we recognize the effectiveness of preventive maintenance only in presence of aging phenomena. Importance measures allow the ranking of the input variables. We propose analytical equations that allow the estimation of the first-order Differential Importance Measure (DIM) on the basis of the Birnbaum measures of components, under the hypothesis of uniform percentage changes of parameters. Without further information than that used for the estimation of “DIM for components,” “DIM for parameters” allows considering separately the importance of random failures, aging phenomena, and preventive and corrective maintenance. A two-step process is proposed for the system improvement, by increasing the components reliability and maintainability performance as much as possible (within the applicable technological limits) and then by optimizing preventive maintenance on them. Some examples taken from the scientific literature are solved in order to verify the correctness of the analytical equations and to show their use.

ДослідженнЯ впливУ прОфілактичнОгО технічнОгО обслуговуваннЯ нА надійністЬ відмОвОстійкОгО джерелА безперебійнОгО електроживленнЯ

Research of preventive maintenance effect on reliability of fault-tolerant uninterruptible power supply is important in determination of the requirements for maintenance. In this paper the objects under consideration are two variants of the fault-tolerant system for uninterruptible power supply with (N+M) and 2×(N+M) redundant configurations, which are provided by preventive maintenance. There are given reliability models for both configurations of faulttolerant system for uninterruptible power supplies, which allows investigating the dependence of their reliability on the frequency of preventive maintenance, in this paper. Reliability models for fault-tolerant systems are formed as graphs of states and transitions. Determination of the reliability parameters is associated with the solution of system of Kolmogorov Chapman differential equations, formed according to the developed graphs. These models are useful both at the design stage (to determine the structure of the fault-tolerant system) and during operation (to determine the requirements for maintenance) of uninterruptible power supply, designed as a fault-tolerant system.

Modeling Maintenance Effect with Failure-Counting

The assessment and modeling of the maintenance effect is an active research topic. In this paper, we proposed a failure- counting-based maintenance effect assessment model (abbreviated as FCME). Specifically speaking, this model assumes that a system failure process during a preventive maintenance interval can be described as an independent failure path. The initial independent failure path can be denoted as the inherent failure path. Furthermore, the current failure can be presented as the sum of the last failure path and the increment that is proportional to the difference between the inherent and last failure path. This proportion is used to represent the preventive maintenance effect. Moreover, the failure path is modeled by a random failure point process model. In order to illustrate the effectiveness of the proposed method, a numerical example is presented based on the data referenced from previous literatures. Then the model is used to assess the preventive maintenance effect of a bus fleet with the real world operating data.