Evaluation of Spare Parts Configuration and Maintenance Strategy of New Air Defense Anti-missile Radar based on Improved AHP and Cloud Gravity Center Theory

2021 ◽  
Author(s):  
Ruoyu Song ◽  
Shihua Liu ◽  
Juan Yu ◽  
Wei Jiang ◽  
Long Xiang
Keyword(s):  
Spare Parts ◽  
Maintenance Strategy ◽  
Gravity Center ◽  
Air Defense

Integrated maintenance/spare parts management for manufacturing system according to variable production rate impacting the system degradation

2020 ◽  
Vol 28 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Sofiene Dellagi ◽  
Wajdi Trabelsi ◽  
Zied Hajej ◽  
Nidhal Rezg
Keyword(s):  
Production Rate ◽  
Preventive Maintenance ◽  
Manufacturing System ◽  
Planning Horizon ◽  
Sensitivity Study ◽  
Spare Parts ◽  
Rate Variation ◽  
Maintenance Strategy ◽  
Spare Parts Management ◽  
The Impact

This study develops an analytical model in order to determine an optimal integrated maintenance plan and spare parts management. We consider a manufacturing system, producing only one type of product, over a finite planning horizon H equal to the sum of all production periods and the production quantity of each period is known. This system is subject to a continuously increasing degradation rate. That is why a preventive maintenance strategy is adopted in order to face the increasing failure rate. We noted that contrarily to the majority of studies in literature, we take into account the impact of the production rate variation on the manufacturing system degradation and consequently on the adopted optimal maintenance strategy. In addition, the real need of spare parts relative to the scheduled maintenance actions is taken into account. In fact, the purpose of our study consists at determining the optimal preventive maintenance frequency and the optimal quantity of spare parts to order by minimizing a total cost, including maintenance and spare parts management. Numerical examples are presented along with a sensitivity study in order to prove the use of the developed model for deriving the optimal integrated strategy for any instance of the problem.

Optimal maintenance strategies for repairable systems with general degree of repair

1991 ◽  
Vol 28 (02) ◽  
pp. 384-396 ◽  
Author(s):  
Wolfgang Stadje ◽  
Dror Zuckerman
Keyword(s):  
Optimal Policy ◽  
Planning Horizon ◽  
Spare Parts ◽  
Inventory Systems ◽  
Maintenance Strategy ◽  
Repairable Systems ◽  
Discounted Cost ◽  
Wide Range ◽  
Optimal Maintenance ◽  
New Research

In this study we examine repairable systems with random lifetime. Upon failure, a maintenance action, specifying the degree of repair, is taken by a controller. The objective is to determine an age-dependent maintenance strategy which minimizes the total expected discounted cost over an infinite planning horizon. Using several properties of the optimal policy which are derived in this study, we propose analytical and numerical methods for determining the optimal maintenance strategy. In order to obtain a better insight regarding the structure and nature of the optimal policy and to illustrate computational procedures, a numerical example is analysed. The proposed maintenance model outlines a new research channel in the area of reliability with interesting theoretical issues and a wide range of potential applications in various fields such as product design, inventory systems for spare parts, and management of maintenance crews.

A bi-objective model for vessel emergency maintenance under a condition-based maintenance strategy

SIMULATION ◽  
2017 ◽  
Vol 94 (7) ◽  
pp. 609-624 ◽  
Author(s):  
Jinlou Zhao ◽  
Liqian Yang
Keyword(s):  
Complex Problem ◽  
Spare Parts ◽  
Condition Based Maintenance ◽  
Maintenance Strategy ◽  
Nsga Ii ◽  
Maintenance Costs ◽  
Inventory Costs ◽  
Penalty Costs ◽  
Proposed Model ◽  
Objective Model

When sailing on the open seas, far from onshore dockyards, if a crucial part of the ship’s machinery fails, the ship will experience a costly event that carries a high risk of seriously affecting ship operations. If the ship receives warning of an impending defect, then it can try to sail to a dockyard and simultaneously order the spare parts needed to fix the problem. In this paper, we define this type of maintenance situation as ‘vessel emergency maintenance’. It is a complex problem, due to uncertainties with both the machinery condition development and spare parts delivery. To solve this problem, our paper proposes a bi-objective model under a condition-based maintenance strategy, with the aim of simultaneously minimizing maintenance costs and maximizing ship reliability. Maintenance costs include four things: (1) fuel consumption costs; (2) renting extra vessels; (3) shipping delay penalty costs; and (4) spare parts inventory costs. Ship reliability is represented by the reliability of the ship’s main engine, and can be described through a stochastic process. To solve this bi-objective model, we employ a non-dominated sorting genetic algorithm II (NSGA-II) to generate the Pareto optimal front of the two objectives. A numerical experiment is presented to demonstrate the applicability of the proposed model. The results indicate that the proposed model can provide emergency maintenance decision support for ship operators while they are sailing at sea.

scholarly journals Preventive Maintenance Topic Models for LNG Containment Systems of LNG Marine Carriers Using Dock Specifications

2019 ◽  
Author(s):  
Ik-Hyun Youn ◽  
Sung-Cheol Kim
Keyword(s):  
Language Processing ◽  
Preventive Maintenance ◽  
Low Temperatures ◽  
Spare Parts ◽  
Liquefied Natural Gas ◽  
Maintenance Strategy ◽  
High Demand ◽  
Containment System ◽  
System Maintenance ◽  
Processing Techniques

The high demand for liquefied natural gas (LNG) requires more LNG carriers (LNGCs) to be in operation. During transportation, there is a high risk due to the required extremely low temperatures and the explosive nature of LNG cargo. Moreover, when there is a lack of experience in operating old LNGCs, there is a serious concern regarding operational accidents. A systematic maintenance strategy, especially for LNG cargo containment systems, is crucial for maintaining safe LNG transportation at sea. The purpose of this study is to develop preventive LNG cargo containment system maintenance models by using LNGC dock specifications from LNGCs of various ages. The dock specifications from a conventional LNGC repairing dock were analyzed using natural language processing techniques in order to develop preventive maintenance models of the LNG cargo containment system. From these results, and by considering the ship’s age, it was found that for young LNGCs the priority for repair should focus on checking routine consumable spare parts by tank inspections, whereas for older LNGCs the focus should be on tank condition maintenance rather than on other facilities. These results are expected to be useful in the development of a maintenance strategy of preventive LNG cargo containment systems in maritime LNG transportation.

Optimal maintenance strategies for repairable systems with general degree of repair

1991 ◽  
Vol 28 (2) ◽  
pp. 384-396 ◽  
Author(s):  
Wolfgang Stadje ◽  
Dror Zuckerman
Keyword(s):  
Optimal Policy ◽  
Planning Horizon ◽  
Spare Parts ◽  
Inventory Systems ◽  
Maintenance Strategy ◽  
Repairable Systems ◽  
Discounted Cost ◽  
Wide Range ◽  
Optimal Maintenance ◽  
New Research

In this study we examine repairable systems with random lifetime. Upon failure, a maintenance action, specifying the degree of repair, is taken by a controller. The objective is to determine an age-dependent maintenance strategy which minimizes the total expected discounted cost over an infinite planning horizon. Using several properties of the optimal policy which are derived in this study, we propose analytical and numerical methods for determining the optimal maintenance strategy. In order to obtain a better insight regarding the structure and nature of the optimal policy and to illustrate computational procedures, a numerical example is analysed. The proposed maintenance model outlines a new research channel in the area of reliability with interesting theoretical issues and a wide range of potential applications in various fields such as product design, inventory systems for spare parts, and management of maintenance crews.

Integrating Performance and Maintenance Programs to Meet AES Cartagena Business Goals

2006 ◽  
Author(s):  
Italo Freitas ◽  
Greg Toomey
Keyword(s):  
Spare Parts ◽  
Combined Cycle ◽  
Plant Performance ◽  
Maintenance Strategy ◽  
Performance Information ◽  
Process Data ◽  
Business Goals ◽  
Maintenance Program ◽  
And Performance ◽  
Proactive Maintenance

It is always a major endeavor and challenge to build a new combined-cycle power plant. This fact combined with having stringent reliability, availability and efficiency contractual terms necessitates a well planned, highly effective maintenance strategy. To further complicate the matter, the company was rolling out a new EAM; SAP. AES Corporation was facing exactly these issues for their new plant in Cartagena, Spain. This paper will describe the approach used by AES to develop a proactive maintenance program that integrates condition and performance information to achieve their goals. The process begins with creating a maintenance strategy using the SRCM® process. From the results of the strategy development SAP-PLM module was configured to support agreed to business process models, asset hierarchy schemes, task list, value lists and spare parts determination. The strategy developed also identified the PdM and ODR technologies to use and lead to the development of the PdM program. It also created the operator driven (ODR) tasks by specifying what equipment is to be watched by operators as part of an equipment health program. Finally, PdM, ODR and appropriate process data were linked together into a decision support system. This information combined with the plant performance information will provide AES an effective, integrated program to manage their plant and equipment. Due to the limited staff to manage the station a software tool was used to lessen the effort to understand the condition of critical equipment based on the data. A discussion of why it is necessary for new and existing plants to create a proactive maintenance program that starts with business processes followed by software and hardware including CMMS, PdM, online monitoring, electronic operator rounds and ends with the right data in these tools is presented. Without the proper data including asset register, criticality, reliability information and condition data the program will not support plant objectives and could potentially cost the company large penalties for non-performance. Examples of work products developed with work flowcharts will be provided. By actively pursing an integrated, proactive solution for the maintenance and performance programs AES will achieve their business objectives from the very beginning of plant commercialization. It will also ultimately lead to savings in not only implementing a complete maintenance program but will provide a solid foundation for managing and improving the program operation of the plant to meet and exceed contractual performance requirements.

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