• International Journal of Reliability and Applications
• /
• v.18 no.1
• /
• pp.1-8
• /
• 2017

In this paper, we study an extended warranty model under minimal repair-replacement warranty (MRRW) which is suggested by Park, Jung and Park (2013). Under MRRW policy, the manufacturer is responsible for providing the minimal repair-replacement services upon the system failures during the warranty period. And if the failure occurs during the extended warranty period, only the minimal repair is conducted. Following the expiration of extended warranty, the user is solely responsible for maintaining the system for a fixed length of time period and replaces the system at the end of such a maintenance period. During the maintenance period, only the minimally repair is given for each system failure. The main purpose of this article is to suggest the extended warranty and replacement model with MRRW. Given the cost structures incurred during the life cycle of the system, we formulate the expected cost and the expected length of life cycle to obtain the expected cost rate.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.42-45
• /
• 2002

Building remodeling concept includes maintenance & repair and renovation. We have long-term repair plan and special repair fund system for the apartment maintenance & repair, but they do not operate well. And laws and ordinances are being revised in relation with renovation. However, more policy improvement and assistance are needed in order to activate the apartment remodeling project. Especially preferential loan and tax reduction policy and deregulation of building provisions are the main tasks for the apartment remodeling.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.1
• /
• pp.61-69
• /
• 2020

Systems such as database and socal network systems have been broadly used, and their unexpected failure, with great losses and sometimes a social confusion, has received attention in recent years. Therefore, it is an important issue to find optimal maintenance plans for such kind of systems from the points of system reliability and maintaining cost. However, it is difficult to maintain a system during its working cycle, since stopping works might incur users some troubles. From the above viewpoint, this paper discusses minimal repair maintenance policy with periodic replacement, while considering the random working cycles. The random working cycle and periodic replacement policies with minimal repair has been discussed in traditional literatures by usually analyzing cases for the nonstopping works. However, maintenance can be more conveniently done at discrete time and even during the working cycle in real applications. So, we propose that periodic replacement is planned at discrete times while considering the random working cycle, and moreover provide a model in which system, with a minimal repair at failures between replacements, is replaced at the minimum of discrete times KT and random cycles Y. The average cost rate model is used to determine the optimal number of periodic replacement.

• Journal of Advanced Marine Engineering and Technology
• /
• v.23 no.6
• /
• pp.785-793
• /
• 1999

There are two kinds of method in ship maintenance. One is the corrective maintenance and the other is the preventive maintenance. For these maintenances recently the stochastic techniques are widely used to keep the maximum availibility and the optimal maintenance period minimizing a given cost function. Thus this paper suggest a method to decide the optimal policy of ship's maintenances by using dynamic programming and the effectiveness of the method is verified through several examples in which failure rates and maintenance data of ship's machineries and parts are given.

• Journal of the Korea Society of Computer and Information
• /
• v.20 no.12
• /
• pp.175-180
• /
• 2015

It is important to maintain information system (IS) following the business and institutional change. Even if successfully developed information systems, we cannot gain the benefit from the systems without the proactive maintenance activities. However, the importance of IS maintenance has not been considered as much as the system development, and we don't have any specific performance management structure. The objective of this study is to identify the relationship between IS maintenance activities and utilization. For empirical test of the hypothesis model, the sample data is collected from public information system sites. Results from multiple regression analysis reveal that proactive maintenance activities including IS maintenance cost increase, improving functionality, and enhancing ease of use have a causal effect on the IS utilization.

• The Korean Journal of Applied Statistics
• /
• v.26 no.1
• /
• pp.151-162
• /
• 2013

Due to a growing demand for the second-hand product, especially for the expensive one, the warranty and maintenance policies for such products have been studied to improve the product reliability of late. In this paper we study a periodic maintenance model for the second-hand product which is purchased by the customer at the age of $x$. When purchased, the dealer provides a warranty of a fixed length during which the product is maintained periodically to reduce the failure rate of the product and thus, to improve the reliability after each maintenance is served. If a failure occurs between two successive maintenances, only minimal repair is conducted. As for the warranty policy, we adopt free non-renewing repair action on each failure, in addition to the periodic maintenance service during the warranty period. Thus, under the given warranty policy, all the maintenance and repair costs incurred during the warranty period are charged to the dealer. For the proposed periodic maintenance scheme, we formulate a cost model to evaluate the expected total cost charged to the dealer during the warranty period and derive an optimal upgrade level of the failure rate at each maintenance to minimize the expected total warranty cost from the perspective of the dealer. We also present numerical results for an optimal upgrade level based on the proposed methods.

• Journal of Korean Society for Quality Management
• /
• v.29 no.2
• /
• pp.46-53
• /
• 2001

In this paper, a preventive maintenance(PM) policy for a repairable system is considered. The failure rate model proposed by Park et at.(2000) is generalized by assuming that after each PM not only the PM slows down the degradation process of the system but also reduces down the system failure rate by a certain fixed amount. Long-run expected cost rate of the PM policy is derived and the properties of joint solution of the optimal PM period and optimal number of PM which minimizes the expected cost rate are obtained. Numerical examples for the case of a Weibull-type failure rate are given.

• Health Policy and Management
• /
• v.8 no.1
• /
• pp.203-230
• /
• 1998

This purposes of this study is to develope policies on the facilities for the elderly care in Korea. Methodology of this study adopts comparative analysis on the facilities for the elderly care in 6 countries which have experienced various problems on the elderly. These 6 countries are Japan, Sweden, America, Australian, England and Germany. Major issues for comparative analysis are the standard of care facilities, residence condition, finance of facilities establishment and expense, operating system, management, and the law and administrative structure about the facilities for the elderly care. The elderly people need various kinds of welfare services such as medical care facilities, nursing home facilities, home care facilities etc.. Thus the public policies for the aging population nations are compose of income maintenance program, health and medical care services and social welfare services. The policies of facilities for elderly care are very important since these policies include the characteristics of income maintenance, me\ulcorner미 care program and welfare program. This study willsupply basic data for the development of facilities for the elderly care in Korea, especially conceming the system and institutional device of the facilities.

• Proceedings of the Korean Reliability Society Conference
• /
• 2005.06a
• /
• pp.131-137
• /
• 2005

In this paper, we propose a Bayesian approach to determine the adaptive preventive maintenance(PM) policy for a general sequential imperfect PM model proposed by Lin, Zuo and Yam(2000) that PM not only reduces the effective age of the system but also changes the hazard rate function. Assuming that the failure times follow Weibull distribution, we adopt a Bayesian approach to update unknown parameters and determine the Bayesian optimal sequential PM policies. Finally, numerical examples of the optimal adaptive PM policy are presented for illustrative purposes.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.16 no.2
• /
• pp.29-36
• /
• 2010

Recently, the system that can eliminate discrimination and barrier to disabled, ensure the substantial independence of disabled and help participation in community of disabled is required. Therefore, the purpose of this study is 'construction of the Barrier-free environment' which members of societies included the disabled can live safely in the daily living environment. To achieve this result, this study is shown establishment and complementary direction of the policy related convenient facilities by comparing between domestic and international policy of the convenient facilities. The results of this study are as follows; Firstly, among the conflicting part between related laws and design standards shold be constantly supplemented. Secondly, policy to promote convenient in residential part is needed. Thirdly, composition of the organization that can support professional housing reconstruction is required. Fourthly, from early stage of policy making, not only opinion reflection of users but also maintenance of convenient facilities, continuous maintenance plan and making a policy for verification system is needed. Finally, when the revision of the existing policies or new policies undergo, 'Barrier-free perspective' should be considered.