• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.82-91
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• 2020

Recently, the research and development of weapon systems have expanded from ILS centered on acquisition costs to LCS, including operating maintenance costs. Regulations define the provision and formula of operating maintenance costs, but this does not consider the characteristics of the design and operation/maintenance of real weapon systems based on engineering calculations. Therefore, this study suggests a simulation design method to complement these areas and produce more accurate operating maintenance costs. The research procedures are as follows. First, the provision and formula of operating maintenance costs were defined to make the simulation results applicable. Second, a simulation model was developed by reviewing design considerations so that the simulation results reflect reality more accurately. The design considerations include the PBS of weapon systems, operation schedules, specifications for operation/maintenance/warehouse facilities, and basic cost information (personnel expense and spare part/equipment cost). This study is expected to be effective in calculating the operating maintenance costs more easily and accurately.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.814-823
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• 2012

Electric power transmission utilities make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability. The development of maintenance strategies for aged components is one of the more effective ways to achieve this goal. The reliability centered approach is a key method in providing optimal maintenance strategies. It considers the tradeoffs between the upfront maintenance costs and the potential costs incurred by reliability losses. This paper discusses the application of the Particle Swarm Optimization (PSO) technique used to find the optimal maintenance strategy for a transmission component in order to achieve the minimum total expected cost composed of Generation Cost (GC), Maintenance Cost (MC), Repair Cost (RC) and Outage Cost (OC). Three components of a transmission system are considered: overhead lines, underground cables and insulators are considered. In regards to aged and aging component, a component state model that uses a modified Markov chain is proposed. A simulation has been performed on an IEEE 9-bus system. The results from this simulation are quite encouraging, and then the proposed approach will be useful in practical maintenance scheduling.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.291-301
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• 2009

This paper presents the optimal design and analysis method of the train overhaul maintenance facility based on the simulation. Because the train is composed of a coach or more, we design the simulation model after analyzing the operation of train into train, coach, coach's body parts and wheel parts and soon. In simulation analysis, we consider the critical (dependent) factors and design (independent) parameters for the selection of alternatives and optimal design. Therefore, Multi Criteria Decision Making (MCDM) is proposed for the selection of alternatives and optimal method in order to find the optimal design factors. The case study for the above approach is used for the electronic locomotive overhaul maintenance facility. This paper provides a comprehensive framework for the train overhaul maintenance facility design using the simulation, MCDM and optimal methods. Therefore, the method developed for this research can be adopted for other enhancements in different but comparable situation.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.4
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• pp.200-206
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• 2022

This study is to develop database by an experimental method for the development of condition based maintenance for auxiliary equipment in marine engine systems. Existing ships have been performing regular maintenance, so the actual measurement data development is very incomplete. Therefore, it is best to develop a database on land tests. In this paper, a database developed by an experimental method is presented. First, failure case analysis and reliability analysis were performed to select a failure mode. For the failure simulation test, a test bed for land testing was developed. The failure simulation test was performed based on the failure simulation scenario in which the failure simulation test plan was defined. A 1.5TB failure simulation database has been developed, and it is expected to serve as a basis for ship failure diagnosis and prediction algorithm model development.

• IE interfaces
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• v.13 no.4
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• pp.680-687
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• 2000

The objectives of this research are to establish the operation scheduling and the preventive maintenance system in order to optimize the operation of mailing center. For the optimal operation scheduling of mailing process, the existing workflow of mailing process and that of required time are investigated prior to simulation modeling. The simulation experiments are conducted to increase the nextday delivery rate. The best alternative whose nextday delivery rate up to 100% is selected based the AHP(Analytic Hierarchy Process) method. The optimal work scheduling of all mailing centers are also presented. In addition, the CMMS(Computerized Maintenance Management System) for preventive maintenance is introduced for efficient operation of highly automated facilities of mailing center.

• IE interfaces
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• v.19 no.3
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• pp.245-254
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• 2006

Equipments in container terminal have a lot of parts, and an equipment breakdown affects the productivity of terminal. In this paper, we develop a maintenance management system for improving reliability, availability and maintainability of equipments in container terminals. The developed system consists of five modules : equipment structure module, equipment operation management module, maintenance control module, spare part control module and data analysis module. The system supports reliability engineers to manage and improve RAM of equipments in container terminals. For example, FMEA, failure state analysis and life distribution parameters estimation are easily or automatically done by the system. This system also provides optimal preventive maintenance intervals by simulation and optimal yearly PM schedules for equipments in container terminal are recommended.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1314-1323
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• 2011

The maintenance of generating units is implicitly related with power system reliability and has a tremendous bearing on the operation of the power system. A technique using a fuzzy search method which is based on fuzzy multi-criteria function has been proposed for GMS (generator maintenance scheduling) in order to consider multi-objective function. In this study, a new technique using combined fuzzy set theory and genetic algorithm(GA) is proposed for generator maintenance scheduling. The genetic algorithm(GA) is expected to make up for that fuzzy search method might search the local solution. The effectiveness of the proposed approach is demonstrated by the simulation results on a practical size test systems.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.4
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• pp.426-434
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• 2020

This paper studies the impact of the maintenance time of anti-ship missile Harpoon on operational availability with real field data. The Harpoon maintenance simulation model is developed as a testbed for identifying the optimal inventory levels on operational availability. Using multiple linear regression analysis and integer programming, the optimal inventory levels of essential assemblies are suggested. Finally, the result of sensitivity analysis shows the quantitative impact of maintenance time on operational availability and inventory costs. The authors believe that this quantitative analysis can support policy decisions to decrease maintenance time of missiles.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.820-825
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• 2006

It is necessary to correspond to building users' claims rapidly as much as possible in order to satisfy user's need, because the final tarket of building maintenance service is user of building. This paper investigates the time taken for receiving users' claims and the time taken for the service organization to respond to the claims in the office building; types of claims and service responses are analysed, through which the response characteristics of the maintenance management organization are evaluated with respect to users' claims. Throughout extensive simulation analysis, important performance measures such as mean time to repair and utilization of maintenance personnels have been investigated.

• Journal of the Korea Society for Simulation
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• v.28 no.4
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• pp.1-10
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• 2019

The Sea Water Reverse Osmosis (SWRO) plant should take into account the availability of the plant from the design stage for long-term and continuous fresh water production. As it occurs, it is necessary to establish a corrective maintenance plan and preventive maintenance plan to maintain availability. In the field of complex engineering structures such as seawater desalination plants, it is difficult to estimate the reliability or availability of the system in a mathematical way. This study develops RAM analysis framework and model, and proposes discrete event simulation model as a application sowtware specialized for seawater desalination plant. Considering the characteristics of the plant maintenance, in case of corrective maintenance, we propose a preventive maintenance policy that not only repairs or replaces a single-broken part, but also simultaneously maintains all accessible parts according to the level of overhaul. A case study was conducted to estimate the availability of the system based on the field data of the seawater desalination plant in Korea and Saudi Arabia. The result was close to the expected availability of the plant.