• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.47-57
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• 2016

As the inventory costs of repairable items in military logistics continue to increase, many studies for optimal inventory level of these items are being carried out in advanced countries, including the US, to reduce these costs. Research on inventory level optimization for repairable items aimed to achieve the availability goal of a system with a MIME(Multi Indenture Multi Echelon) repair policy structure first began with Sherbrooke's METRIC and developed into various types. This research is to analyze and compare recent V-METRIC related studies to search for another variation in this field. This paper mainly looks at how to determine optimum inventory level for each repairable item to achieve a specific availability target within a limited budget, and also how to minimize inventory cost while achieving its availability target by determining optimal inventory level of each repairable item.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.301-307
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• 1998

This paper proposes free warranty interval for repairable items when the failure types of item are considered. Failure types are classified into major failure and minor failure. If major failure occurs during warranty period, the item is replaced and if minor failure occurs during warranty period, the item is minimally repaired. This paper determines the optimum free warranty interval which minimizes total expected cost of the free warranty cost model. Numerical example is shown in which failure time of item has weibull distribution.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.3
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• pp.226-232
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• 2001

This paper presents an efficient method for the problem of determining the spare inventory level of a multi-echelon repairable-item inventory system. We consider the system with two levels of inventory, two levels of service and with a general service time distribution. We propose an algorithm that determines the spare inventory level to satisfy the minimum fill rate with the minimum cost. Experimental results show that the algorithm is accurate and efficient.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.40
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• pp.23-28
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• 1996

This paper deals with performance measures for recoverable item control where the demand process is time-dependent. The performance measure is essential for modelling a multi-echelon inventory problem for repairable items. Most repairable items are expensive and have a great influence on the performance of equipments. Thus the information on these items is very useful to the decision maker. The purpose of this paper is to derive the system performance measure and the part(component) performance measure considering a cannibalization policy under the dynamic environment.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.3
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• pp.1-11
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• 1999

We consider the problem of determining the spare inventory level for a multiechelon repairable-item inventory system. Our model extends the previous results to the system which has an inventory at the central depot as well as bases. We develop an optimal algorithm to find spare inventory leveis, which minimize the total expected cost and simultaneously satisfy a specified minimum service rate. The algorithm is tested using problems of various sizes to verify the efficiency and accuracy.

• Journal of Korean Society for Quality Management
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• v.22 no.3
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• pp.54-65
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• 1994

A hybrid warranty policy for a repairable item is considered. Assuming that minimal repairs ar e performed for failures during warranty period, present worth of warranty cost is derived from a supplier's viewpoint. An optimal preventive periodic replacement policy for the case is also derived from a user's viewpoint Numerical examples are presented in order to explain the results.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.81-90
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• 1993

This article concerns the problem of determining the optimal spare inventory level for multiechelon repairable-item inventory system. The system we are concerned has several bases and a central depot. When an item fails, it is dispatched to a repair facility and, a spare, if available, is plugged in immediately. When the failed item is repaired, it is sent to the base and either used to fill a backorder or stored at a spare inventory point. We develop an optimal algorithm to find the spare inventory level at each base spareswhich minimizes the total expected cost and, simultaneously, satisfies a specified minimum service rate. The algorithm is applied to examples with good results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.15-23
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• 1998

This paper concerns the problem of determining the spare inventory level for multi-echelon repairable-item inventory system with finite number of operating items. We consider the system which has several bases and a central depot. When an item fails, it is dispatched to a repair facility and, a spare, if available, is plugged in immediately. When the failed item is repaired, it is sent to the base and either is used to fill a backorder or is stored at a spare inventory point. Using queueing network, we develop an algorithm to find the spare inventory level which minimizes the total expected cost and, simultaneously, satisfies a specified minimum fill rate. The results of the algorithm clearly indicate that the algorithm successfully generate output with optimal solution.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.281-293
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• 2004

o 고장률$\lambda$(t)=(equation omitted)는 부품의 모집단에 적용되는 척도 o 초기고장기간, 우발고장기간, 마모고장기간은 Repairable system의 성격 o $\beta$＞1인 Weibull분포, Normal분포 등을 따르는 item은 고장률이 처음부터 증가하므로 수명=0 (\ulcorner) o y축을 고장강도 $\rho$(t)=(equation omitted)로 표현하면 Repairable system에서 설명이 잘됨.(중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.99-107
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• 1997

We consider a multiechelon repairable-item inventory system where several bases are supported by a central depot and the external repair facilities. Unlike METRIC- based models, there are only a finite number of repair channels at each base, central depot and the external repair facilities. It is desired to find repair capacities and spares level which together guarantee a specified service level at minimum cost. Closed queueing network theory is used to model the stochastic process. The purpose of this paper is to derive the steady-state distributions of this system.