The Optimal Maintenance Period for Repairable Product after Warranty Expiration under Renewing Warranty

2010 ◽  
Vol 118-120 ◽  
pp. 860-865 ◽  
Author(s):  
Z.Y. Hu ◽  
Li Yang Xie
Keyword(s):  
Life Cycle ◽  
Failure Rate ◽  
Maintenance Period ◽  
Cost Rate ◽  
Numerical Example ◽  
Warranty Period ◽  
Optimal Maintenance ◽  
The Cost ◽  
Cost Factors ◽  
Increasing Function

A model of the optimal maintenance period for repairable product after warranty expiration under renewing warranty is proposed. In the process to fulfilling warranty, the failures of product within warranty period happen randomly, the replacements of products successively failed with warranty period form a renewing process. Given failure rate of product, the period of fulfilling warranty is function of warranty period. User purchasing a product is considered an investment; the period of fulfilling warranty and the maintenance period after warranty make up the life cycle of product investment. Taking various cost factors into account, making model of the cost rate in life cycle of product investment under renewing warranty, the cost rate is function of maintenance period. Give the failure rate of product is an increasing function, it is derived that there is unique optimal maintenance period minimizing the cost rate. Finally, numerical example is given for illustration.

Determination of optimal post-warranty variable maintenance period for repairable second-hand product based on mean residual life

2021 ◽  
pp. 1748006X2110629
Author(s):  
Jae-Hak Lim ◽  
Dae Kyung Kim ◽  
Dong Ho Park
Keyword(s):  
Life Cycle ◽  
Preventive Maintenance ◽  
Residual Life ◽  
Mean Residual Life ◽  
Maintenance Period ◽  
Life Distribution ◽  
Expected Cost ◽  
Cost Rate ◽  
Warranty Period ◽  
Significant Difference

Due to the increased transactions of second-hand products in the market, the optimization of maintenance strategy for the second-hand product has become very important issue to attract a great attention from many researchers of late. This paper proposes a new post-warranty strategy with a variable self-maintenance period for the second-hand product, assuming that the product is replaced by another one on the first failure following a fixed length of post-warranty self-maintenance period. During the non-renewing warranty period, the product is subject to preventive maintenance periodically at a prorated cost while only minimal repair is implemented at each failure by the dealer. The main goal of this study is to determine an optimal length of post-warranty self-maintenance period which minimizes the expected cost rate per unit time during the product’s life cycle from the user’s perspective. This approach considers not only the periodic preventive maintenance during the warranty period, but also the remaining life distribution of the product after the warranty expires, which is the significant difference of this work from many existing maintenance policies. For this purpose, we formulate the expected length of life cycle and evaluate the expected total cost incurred during the life cycle of the second-had product which is purchased at the age of [Formula: see text] The existence of the optimal self-maintenance period is proved analytically under mild conditions and the proposed maintenance model is compared with an existing model with regard to the expected cost rate. Finally, assuming that the life distribution of the product follows a Weibull distribution, the effect of relevant parameters on the optimal self-maintenance period is analyzed numerically.

scholarly journals Economic Analysis for Setting Appropriate Repair Cycles on the Fixed Materials and Facilities in the Public Rental Housing

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Sung-Min Choi ◽  
Yeon-Sil Lee
Keyword(s):  
Life Cycle ◽  
Economic Analysis ◽  
Life Cycle Cost ◽  
Rental Housing ◽  
The Public ◽  
Public Rental Housing ◽  
Maintenance Cycle ◽  
Minimum Age ◽  
Optimal Maintenance ◽  
The Cost

Currently, repair and maintenance cycles that follow the completion of construction facilities lead to the necessitation of subsequent data on the analysis of study and plan for maintenance. As such, an index of evaluation was drafted and a plan of maintenance cycle was computed using the investigation data derived from surveying target housing units in permanent rental environmental conditions, with a minimum age of 20 years, and their maintenance history. Optimal maintenance and replacement methods were proposed based on this data. Economic analysis was conducted through the Risk-Weighted Life Cycle Cost (RWLCC) method in order to determine the cost analysis of maintenance life cycle methods used for repair. Current maintenance cycle methods that have been used for 20 years were also compared with alternative maintenance cycles.

Sequential imperfect preventive maintenance policy with random maintenance quality under reliability limit

2011 ◽  
Vol 225 (8) ◽  
pp. 1926-1935 ◽  
Author(s):  
Z Wang ◽  
J Yang ◽  
G Wang ◽  
G Zhang
Keyword(s):  
Failure Rate ◽  
Preventive Maintenance ◽  
Average Cost ◽  
Numerical Control ◽  
Maintenance Policy ◽  
Cost Rate ◽  
Proposed Model ◽  
Optimal Maintenance ◽  
Average Cost Rate ◽  
Optimal Maintenance Policy

To determine the optimal maintenance number for a system with random maintenance quality in infinite time horizon, a sequential imperfect preventive maintenance model considering reliability limit is proposed. The proposed model is derived from the combination of the Kijima type virtual age model and the failure rate adjustment model. Maintenance intervals of the proposed model are obtained through an iteration method when both failure rate increase factor and maintenance restoration factor are random variables with a uniform distribution. The optimal maintenance policy is presented by minimizing the long-run average cost rate. A real numerical example for the failures of numerical control equipment is given to demonstrate the proposed model. Finally, a discussion is presented to show how the optimal average cost rate depends on the different cost parameters. The results show that in order to satisfy the practical requirements of high reliability, it is necessary and worthwhile to consider the system's reliability limit in preventive maintenance practice.

scholarly journals Methodical approach to forecasting costs for updating and using arms and military equipment park

2021 ◽  
pp. 37-45
Author(s):  
Oleksii Leontiev ◽  
Maryna Naumenko
Keyword(s):  
Life Cycle ◽  
Service Life ◽  
Failure Rate ◽  
Methodological Approach ◽  
Operating Conditions ◽  
Operating Costs ◽  
Residual Service Life ◽  
Purchase Price ◽  
Military Equipment ◽  
The Cost

A methodological approach to forecasting the cost costs at the main stages of the life cycle of a sample of weapons and military equipment, as one of the most important carriers of the capabilities of military organizational-staff formations, is proposed, which is carried out when substantiating measures for developing the capabilities of troops in the course of long-term and medium-term defense planning. The methodological approach is based on the use of the concept of a typical distribution of the cost of the life cycle of a sample by stages and stages, which allows in a formalized form to link costs at each stage of the purchase price of a serial product of a sample of weapons and military equipment of a specific type and type, taking into account the choice of a specific way of obtaining weapons and military equipment. It is proposed to forecast the volume of necessary costs at the stage of operation and support, taking into account the uneven distribution of these costs during this stage of the life cycle of a separate product. For this, it is proposed to divide the entire period of the duration of the operation stage into two main parts. The first part corresponds to the operating conditions of the product with a constant failure rate of the equipment after the completion of a short running-in process, and the operating costs per unit of time on it are considered the same throughout its duration. A formalized expression is proposed for obtaining the predicted value of these costs depending on the purchase price of the product. In the second part of the period of operation and support of a product of weapons and military equipment, operating costs per unit of time change over time according to an exponential law, reflecting the fact that operating costs increase with an increase in the failure rate as it approaches the assigned service life, which corresponds to the laws, known from the general theory of reliability of technology. The specifics of forecasting the costs of operation and support of a product obtained by import and which has already been in operation and has a residual service life have been determined.

OPTIMAL CONTROL OF A SIMPLE IMMIGRATION PROCESS THROUGH THE INTRODUCTION OF A PREDATOR

2003 ◽  
Vol 17 (1) ◽  
pp. 119-135 ◽  
Author(s):  
E.G. Kyriakidis
Keyword(s):  
Optimal Control ◽  
Real Line ◽  
Average Cost ◽  
Pest Population ◽  
Cost Rate ◽  
Entire Real Line ◽  
Long Run ◽  
Immigration Process ◽  
The Cost ◽  
Increasing Function

This article is concerned with the problem of controlling a simple immigration process, which represents a pest population, by the introduction of a predator. It is assumed that the cost rate caused by the pests is an increasing function of their population size and that the cost rate of the controlling action is constant. The existence of a control-limit policy that minimizes the expected long-run average cost per unit time is established. The proof is based on the variation of a fictitious parameter over the entire real line.

OPTIMAL DISCRETE-TIME PERIODIC REPLACEMENT POLICY FOR REPAIRABLE PRODUCTS UNDER FREE MINIMAL REPAIR WARRANTY

2012 ◽  
Vol 29 (03) ◽  
pp. 1240020
Author(s):  
FU-MIN CHANG ◽  
YU-HUNG CHIEN
Keyword(s):  
Failure Rate ◽  
Discrete Time ◽  
Replacement Policy ◽  
Cost Models ◽  
Minimal Repair ◽  
Warranty Period ◽  
Long Run ◽  
Periodic Replacement ◽  
The Cost ◽  
Time Periodic

This paper presents the effects of a free minimal repair warranty (FMRW) on the periodic replacement policy under discrete operating circumstance. For the discrete-time periodic replacement policy, a product is preventively replaced at pre-specified operation cycles N, 2N, 3N, … (N = 1, 2, …). When the product fails, a minimal repair is performed at the time of failure and the failure rate is not disturbed by each repair. From the customer's perspective, the cost models are developed for both a warranted and a nonwarranted product, and the corresponding optimal periodic replacement policies are derived such that the long-run expected cost rates are minimized. Under the assumption of the discrete time increasing failure rate (IFR), the existence and uniqueness of the optimal N* are shown, and the impacts of a FMRW on the optimal replacement policies are investigated analytically. We found that the optimal N* for a warranted product should be adjusted toward the end of the warranty period.

scholarly journals Effects of safety barrier life cycle cost factors - identification and analysis

2018 ◽  
Vol 231 ◽  
pp. 01013
Author(s):  
Adam Kristowski ◽  
Beata Grzyl ◽  
Anna Gobis ◽  
Łukasz Jeliński
Keyword(s):  
Life Cycle ◽  
Service Life ◽  
Life Cycle Cost ◽  
Field Data ◽  
Cost Structure ◽  
Safety Barrier ◽  
Safety Barriers ◽  
The Cost ◽  
Cost Factors ◽  
Very High

The costs borne by road infrastructure authorities for managing and maintaining road devices such as safety barriers may be very high. This has prompted the need for identifying and analysing in detail all factors that influence the costs of safety barriers throughout their service life. To meet that need, the authors used international experience and field data collected under the LifeRoSE project to define the cost structure and, as a next step, to analyse factors that are relevant to the costs actually incurred.

scholarly journals Determination of Optimal Warranty Period with Preventive Maintenance Actions for Items from Heterogeneous Populations

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Minjae Park
Keyword(s):  
Repair Time ◽  
Minimal Repair ◽  
Optimal Length ◽  
Repair Service ◽  
Expected Cost ◽  
Heterogeneous Populations ◽  
Cost Rate ◽  
Warranty Period ◽  
Optimal Maintenance ◽  
Warranty Length

In this study, we develop an optimal maintenance policy with replacement service and minimal repair service for items from heterogeneous populations and determine the optimal warranty length and repair time threshold. We consider the information-based repair-replacement policy model and develop the formula to evaluate the expected cost rate during the product life cycle. A general formulation is derived for the expected cost rate under a warranty policy for items of heterogeneous populations. When a replacement service and minimal repair service are provided for a failed item, then an item from a weak population has the property of an item from a weak population after service. Similarly, an item from a strong population has the property of an item from a strong population after service. We define the optimal maintenance strategies to minimize the expected cost rate with failure time and repair time for items with heterogeneous reliability characteristics. The effects of parameters of the intensity function for the failure times on the optimal length of the warranty period are studied numerically. Assuming that the product deteriorates, we illustrate the proposed approach using numerical applications and observe the impacts of relevant parameters on the optimal length of the warranty period.

scholarly journals A Research on the Combined Maintenance Strategy for Production Line Equipment Based on Mixed Failure Rate

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Binbin Xu ◽  
Ziyue Wang ◽  
Wei Luo ◽  
Tianqi Ma ◽  
Hao Huang
Keyword(s):  
Failure Rate ◽  
Production Line ◽  
Optimal Number ◽  
Entropy Method ◽  
Maintenance Cost ◽  
Analytic Hierarchy ◽  
Maintenance Costs ◽  
Cost Rate ◽  
Age Regression ◽  
Optimal Maintenance

In order to improve the reliability of the production line and reduce its maintenance costs, this paper establishes preventive maintenance (PM) models of the equipment, which are classified into different levels based on mixed failure rate. The differential and targeted maintaining strategies are formulated as well. First, a method for dividing important equipment and secondary equipment of a production line based on grey interval Analytic Hierarchy Process- (AHP-) Entropy method is proposed. Next, the dynamic service age regression factor and the dynamic failure rate increasing factor are combined to establish a mixed failure rate model. Finally, for the important equipment and secondary equipment, two PM models are established with the constraint of reliability, the objective of maximum availability, and minimum maintenance cost rate to determine the optimal number of PM and cycles. Combined with an example of production line equipment, the optimal maintenance strategies for important equipment and secondary equipment are obtained. The result verified the feasibility of the model, which effectively improved the reliability of the production line equipment and reduced maintenance costs.

IDENTIFICATION OF THE KEY FACTORS FOR ACCURATE LIFE-CYCLE COST ESTIMATION FOR CONSTRUCTION

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Ayedh Alqahtani ◽  
Andrew Whyte
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Prediction Models ◽  
Key Factors ◽  
Plant Resources ◽  
Factors Affecting ◽  
Low Visibility ◽  
The Cost ◽  
Cost Factors

A major limitation of Life-Cycle Cost (LCC) estimation/prediction modelling is the current typical reliance only on those factors that can be readily quantified and come easily to hand. While estimation of the cost of the most common labor, material and plant resources receive consideration because of their high visibility factor, there are several non-cost factors (low visibility factors) affecting the estimate that are often overlooked and, it is argued here, require equal consideration in estimation processes that seek optimum accuracy. Unfortunately, such (low-visibility) factors are neglected or ignored by current prediction models. Identification of these non-cost factors (low visibility factors) affects LCC estimate accuracy and can improve estimation process confidence. This paper critically reviews secondary research on identification of these important non-cost factors and subsequently determines their influence on the accuracy level(s) of construction cost estimation.

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