On the application of quasi-renewal theory in optimization of imperfect maintenance policies

2005 ◽  
Author(s):  
Sang-chin Yang ◽  
Te-wei Lin
Keyword(s):  
Renewal Theory ◽  
Imperfect Maintenance ◽  
Maintenance Policies

Availability analysis and maintenance optimization for multiple failure mode systems considering imperfect repair

2021 ◽  
pp. 1748006X2110127
Author(s):  
Qingan Qiu ◽  
Baoliang Liu ◽  
Cong Lin ◽  
Jingjing Wang
Keyword(s):  
Failure Modes ◽  
Maintenance Cost ◽  
Imperfect Maintenance ◽  
Maintenance Policy ◽  
Cost Rate ◽  
Availability Analysis ◽  
Long Run ◽  
Optimal Maintenance ◽  
Maintenance Policies ◽  
Periodic Inspections

This paper studies the availability and optimal maintenance policies for systems subject to competing failure modes under continuous and periodic inspections. The repair time distribution and maintenance cost are both dependent on the failure modes. We investigate the instantaneous availability and the steady state availability of the system maintained through several imperfect repairs before a replacement is allowed. Analytical expressions for system availability under continuous and periodic inspections are derived respectively. The availability models are then utilized to obtain the optimal inspection and imperfect maintenance policy that minimizes the average long-run cost rate. A numerical example for Remote Power Feeding System is presented to demonstrate the application of the developed approach.

Imperfect maintenance policies for deteriorating production systems

1998 ◽  
Vol 55 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Sheng-Tsaing Tseng ◽  
Ruey Huei Yeh ◽  
Wen-Tsung Ho
Keyword(s):  
Production Systems ◽  
Imperfect Maintenance ◽  
Maintenance Policies

scholarly journals Parameter Estimation of a Reliability Model of Demand-Caused and Standby-Related Failures of Safety Components Exposed to Degradation by Demand Stress and Ageing That Undergo Imperfect Maintenance

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
S. Martorell ◽  
P. Martorell ◽  
A. I. Sánchez ◽  
R. Mullor ◽  
I. Martón
Keyword(s):  
Parameter Estimation ◽  
Nuclear Power ◽  
Likelihood Estimation ◽  
Real Data ◽  
Parameters Estimation ◽  
Model Parameters ◽  
Reliability Model ◽  
Imperfect Maintenance ◽  
Maintenance Policies

One can find many reliability, availability, and maintainability (RAM) models proposed in the literature. However, such models become more complex day after day, as there is an attempt to capture equipment performance in a more realistic way, such as, explicitly addressing the effect of component ageing and degradation, surveillance activities, and corrective and preventive maintenance policies. Then, there is a need to fit the best model to real data by estimating the model parameters using an appropriate tool. This problem is not easy to solve in some cases since the number of parameters is large and the available data is scarce. This paper considers two main failure models commonly adopted to represent the probability of failure on demand (PFD) of safety equipment: (1) by demand-caused and (2) standby-related failures. It proposes a maximum likelihood estimation (MLE) approach for parameter estimation of a reliability model of demand-caused and standby-related failures of safety components exposed to degradation by demand stress and ageing that undergo imperfect maintenance. The case study considers real failure, test, and maintenance data for a typical motor-operated valve in a nuclear power plant. The results of the parameters estimation and the adoption of the best model are discussed.

Continuous improvement of imperfect maintenance actions in PAS and PAR models

2021 ◽  
pp. 1748006X2110016
Author(s):  
Thiago Lima de Barros ◽  
Rodrigo Sampaio Lopes
Keyword(s):  
Continuous Improvement ◽  
Point Of View ◽  
Imperfect Maintenance ◽  
Numerical Application ◽  
Hidden Failure ◽  
Maintenance Policies ◽  
Over Time

In this paper, an unavailability model is proposed to define the test and maintenance policies of systems that are subject to hidden failure and degradation, assuming practices of continuous improvement (CI) under imperfect maintenance actions with Proportional Age Setback (PAS) and Proportional Age Reduction (PAR). For this, two CI equations are analyzed to estimate the progress of maintenance effectiveness over time, and a maximum unavailability constraint is incorporated into the model for evaluation of safety point of view. A numerical application was performed, and the results showed that by adopting CI practices over maintenance actions, the unavailability of the system is reduced in greater proportion over time, besides contributing positively to safety.

Research on Spare Part Requirement for Repairable System Based on the Quasi-Renewal Model

2013 ◽  
Vol 401-403 ◽  
pp. 2349-2353
Author(s):  
Tian Bin Liu ◽  
Jian She Kang ◽  
Zhi Feng You
Keyword(s):  
Life Cycle Cost ◽  
Renewal Theory ◽  
Spare Part ◽  
Maintenance Management ◽  
Repairable System ◽  
Imperfect Maintenance ◽  
Repairable Systems ◽  
Lower And Upper Bounds ◽  
Important Approach ◽  
Forecast Models

The spare part requirement forecast is the base of maintenance management. The exact requirement forecast an important approach to improve availability and safety of the equipments and reducing the life cycle cost of equipments. The spare part requirement are not exactly forecasted under the traditional renewal suppose, hence it easily cause waste of money and backlog of goods. To improve the ability of repairable system spare part supporting under the imperfect maintenance, this paper researches on the spare part requirement forecast for the repairable systems under imperfect maintenance, provides the spare part requirement forecast models based on quasi-renewal theory and calculates the lower and upper bounds of systems availability. Finally, an example reveals the efficiency and operability of the model.

Imperfect maintenance model for estimating aircraft fleet availability

2017 ◽  
Vol 89 (2) ◽  
pp. 338-346 ◽  
Author(s):  
Aleksandar Knezevic ◽  
Ljubisa Vasov ◽  
Slavisa Vlacic ◽  
Cedomir Kostic
Keyword(s):  
Intermediate Level ◽  
Imperfect Maintenance ◽  
Maintenance Policy ◽  
Content Type ◽  
Reliability Parameters ◽  
Optimal Maintenance ◽  
Maintenance Policies ◽  
Optimal Maintenance Policy ◽  
Maintenance Model

Purpose The purpose of this paper is to define conditions under which improved availability of fleet of G-4 jet trainers is obtained, and optimization of intermediate-level maintenance through imperfect maintenance model application. This research has been conducted based on available knowledge, and experience gained by performing intermediate-level maintenance of Serbian Air Force aircrafts. Design/methodology/approach Analysis of the data collected from daily maintenance reports, and the analysis of maintenance technology and organization, was performed. Based on research results, a reliability study was performed. Implementation of imperfect maintenance with its models of maintenance policies (especially a quasi-renewal process and its treating of reliability and optimal maintenance) was proposed to define new maintenance parameters so that the greater level of availability could be achieved. Findings The proposed methodology can potentially be applied as a simple tool to estimate the present maintenance parameters and to quickly point out some deficiencies in the analyzed maintenance organization. Validation of this process was done by conducting a reliability case study of G-4 jet trainer fleet, and numerical computations of optimal maintenance policy. Research limitations/implications The methodology of the availability estimation when reliability parameters were not tracked by the maintenance organization, and optimization of intermediate-level maintenance, has so far been applied on G-4 jet trainers. Moreover, it can be potentially applied to other aircraft types. Originality/value Availability estimation and proposed optimization of intermediate maintenance is based on a survey of data for three years of aircraft fleet maintenance. It enables greater operational readiness (due to a military rationale) with possible cost reduction as a consequence but not as a goal.

Progressive maintenance policy for multiple repairable systems with imperfect maintenance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Garima Sharma ◽  
Rajiv Nandan Rai
Keyword(s):  
Power Plants ◽  
Maintenance Cost ◽  
Mean Residual Life ◽  
Time Interval ◽  
Imperfect Maintenance ◽  
Repairable Systems ◽  
Maintenance Policy ◽  
Data Set ◽  
Content Type ◽  
Maintenance Policies

PurposeDegradation of repairable components may not be similar after each maintenance activity; thus, the classic (traditional-time based) maintenance policies, which consider preventive maintenance (PM), age-based maintenance and overhauls to be done at fixed time interval, may fail to monitor the exact condition of the component. Thus, a progressive maintenance policy (PMP) may be more appropriate for the industries that deal with large, complex and critical repairable systems (RS) such as aerospace industries, nuclear power plants, etc.Design/methodology/approachA progressive maintenance policy is developed, in which hard life, PM scheduled time and overhaul period of the system are revised after each service activity by adjusting PM interval and mean residual life (MRL) such that the risk of failure is not increased.FindingsA comparative study is then carried out between the classic PM policy and developed PMP, and the improvement in availability, mean time between failures and reduction in maintenance cost is registered.Originality/valueThe proposed PMP takes care of the equipment degradation more efficiently than any other existing maintenance policies and is also flexible in its application as the policy can be continuously amended as per the failure profile of the equipment. Similar maintenance policies assuming lifetime distributions are available in the literature, but to ascertain that the proposed PMP is more suitable and applicable to the industries, this paper uses Kijima-based imperfect maintenance models. The proposed PMP is demonstrated through a real-time data set example.

Stochastic Models in Preventive Maintenance Policies

2014 ◽  
Vol 1016 ◽  
pp. 802-806
Author(s):  
Onur Gölbaşı ◽  
Nuray Demirel
Keyword(s):  
Poisson Process ◽  
Stochastic Models ◽  
Preventive Maintenance ◽  
Operating Cost ◽  
Replacement Policy ◽  
Market Demand ◽  
Imperfect Maintenance ◽  
Maintenance Policy ◽  
Maintenance Policies ◽  
Age Replacement

In recent decades, philosophy behind maintenance has varied consistently due to the changes in complexity of designs, advances in automation and mechanization, adaptation to the fast growing market demand, commercial computation in the sectors, and environmental issues. In mid-forties, simplicity of designs, limited maintenance opportunities, and immaturity of trade culture made enough to performonly fix it when it brokeapproach, i.e. corrective maintenance, after failures. Last quarter of the 21thcentury made essential to constitute more conservative and preventive maintenance policies in order to ensure safety, reliability, and availability of systems with longer lifetime and cost effectiveness. Preventive maintenance can provide an economic saving more than 18% of operating cost of systems. In this basis, various stochastic models were proposed as a tool to constitute a maintenance policy to measure system availability and to obtain optimal maintenance periods. This paper presents a general perspective on common stochastic models in maintenance planning such as Homogenous Poisson Process, Non-Homogenous Poisson Process, and Imperfect Maintenance. The paper also introduces two common maintenance policies, block and age replacement policy, using these stochastic models.

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