Verification of Availability Guarantees in HVDC Projects Estimation and Optimization of the Impact from Corrective and Preventive Maintenance

2018 ◽  
pp. 48-59
Author(s):  
Michael Knochenhauer ◽  
Lena Olsson ◽  
Sixten Alm
Keyword(s):  
Preventive Maintenance ◽  
The Impact

scholarly journals Konsep Persediaan Minimum Maksimum Pengendalian Part Alat Berat Tambang PT Semen Padang

2016 ◽  
Vol 11 (1) ◽  
pp. 203 ◽  
Author(s):  
Dio Putera Hasian
Keyword(s):  
Preventive Maintenance ◽  
Control Policy ◽  
Service Level ◽  
High Demand ◽  
Heavy Equipment ◽  
Production Activity ◽  
Inventory Control Policy ◽  
Data Consumption ◽  
Demand Rate ◽  
The Impact

Bureau of mining heavy equipment maintenance at PT. Semen Padang have task in maintenance mine heavy equipment with preventive maintenance although breakdown maintenance. Part inventory is needed to make this activity work properly. If stockout happened will have the impact to PT.Semen Padang mining and production activity. To solve this problem, minimum-maximum inventory control policy is used to give an optimum value of inventory mine heavy equipment. This research is focused in filter and lubricant inventory because they have high demand rate. Data consumption filter and lubricant from January until December 2010 is used in this research. The service level that used is 95%. The result is quantity optimum inventory mine heavy equipment at filter and lubricant with application part inventory of mine heavy equipment. Because it can keep stockout although excess inventory.Keywords: stockout, optimum, inventory

scholarly journals The impact of preventive maintenance practices on manufacturing performance: A proposed model for SMEs in Malaysia

2016 ◽  
Author(s):  
Halim Mad Lazim ◽  
Che Azlan Taib ◽  
Hendrik Lamsali ◽  
Mohamed Najib Saleh ◽  
Chandrakantan Subramaniam
Keyword(s):  
Preventive Maintenance ◽  
Proposed Model ◽  
Manufacturing Performance ◽  
The Impact

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 PREVENTIVE-MAINTENANCE WARRANTY POLICIES FOR REPAIRABLE PRODUCTS WITH AGE-DEPENDENT MAINTENANCE COSTS

2005 ◽  
Vol 12 (02) ◽  
pp. 111-125 ◽  
Author(s):  
RUEY HUEI YEH ◽  
MING-YUH CHEN
Keyword(s):  
Optimal Policy ◽  
Preventive Maintenance ◽  
Life Time ◽  
Optimal Number ◽  
Closed Form Expression ◽  
Minimal Repair ◽  
Maintenance Costs ◽  
Special Cases ◽  
Age Dependent ◽  
The Impact

This paper develops a mathematical model to derive the optimal preventive maintenance warranty (PMW) policy for repairable products with age-dependent maintenance costs. Under a PMW, any product failures are rectified by minimal repair, and additional preventive maintenance actions are carried out within the warranty period. When the costs for preventive maintenance and minimal repair are age-dependent, the optimal number of preventive maintenance actions, corresponding maintenance degrees, and the maintenance schedule for designing a PMW policy are derived here such that the expected total warranty cost is minimized. Under some reasonable conditions, we show that there exists a unique optimal PMW policy in which the product is maintained periodically with the same preventive maintenance degree. Using this property, an efficient algorithm is provided to search for the optimal policy. Some related models developed in the literature are discussed and these models are in fact special cases of the model proposed in this paper. Furthermore, when the life-time distribution of a product is Weibull, a closed-form expression of the optimal policy is obtained. Finally, the impact of providing preventive maintenance is evaluated through numerical examples.

scholarly journals Ergonomics in Semiconductor Wafer Manufacturing

2013 ◽  
Vol 10 ◽  
pp. 231-235
Author(s):  
Wai Yi Foong ◽  
Amir Hamzah bin Hassan
Keyword(s):  
Preventive Maintenance ◽  
Material Handling ◽  
Automated Guided Vehicle ◽  
Lot Size ◽  
Semiconductor Wafer ◽  
Manual Material Handling ◽  
The Impact ◽  
Wafer Manufacturing

In semiconductor wafer manufacturing, there are only a few processes but many steps. Each wafer must go through the processes multiple times (steps) and sometimes not in the same sequence. All the wafers in lot size of 25 pieces are transferred between the processes using an Automated Guided Vehicle from stocker to stocker. Then, the wafers are manually transferred to the processing tool. Although the tools are designed per SEMI S2/S8 standards [1,, the equipment technician can get into awkward postures when performing the preventive maintenance. Both the manual material handling between the tools and awkward postures during preventive maintenance can pose an ergonomic challenge. However, some techniques can be used to minimize the impact. This paper shares the techniques which can ease ergonomic problems in semiconductor wafer manufacturing

scholarly journals A New Maintenance Optimization Model Based on Three-Stage Time Delay for Series Intelligent System with Intermediate Buffer

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Xiaolei Lv ◽  
Qinming Liu ◽  
Zhinan Li ◽  
Yifan Dong ◽  
Tangbin Xia ◽  
...  
Keyword(s):  
Time Delay ◽  
Preventive Maintenance ◽  
Intelligent System ◽  
Buffer Stock ◽  
Normal Operation ◽  
Series System ◽  
Model Based ◽  
The Impact ◽  
Series Systems ◽  
Maintenance Model

For the maintenance problem of intelligent series system with buffer stock, a preventive maintenance model based on the threestage time delay theory is proposed. Firstly, the intelligent series system is decomposed into n − 1 virtual series systems by using approximate decomposition method. The impact factor is introduced to establish the failure rate and maintenance rate model of each virtual machine. Secondly, a preventive maintenance model based on the three-stage time delay theory is proposed for each virtual series system. The machine state from normal operation to failure stage is divided into three steps: initial defect, serious defect, and fault, and different distribution functions are defined in different stages to simulate the degradation process of the machine. Based on the three-stage time delay theory, the machine cost ratio model was established by taking the machine monitoring time and buffer stock as decision variables and the minimum unit time cost rate as objective function. Finally, the rationality and validity of the model are verified by an example analysis, which provides a basis for the maintenance of the intelligent series system.

A decision model for warranted second-hand products considering upgrade level, past age, preventive maintenance and sales volume

2018 ◽  
Vol 24 (4) ◽  
pp. 544-558
Author(s):  
Mohamed N. Darghouth ◽  
Anis Chelbi
Keyword(s):  
Preventive Maintenance ◽  
Decision Model ◽  
Optimal Solution ◽  
Expected Profit ◽  
Sales Volume ◽  
Content Type ◽  
Effort Level ◽  
Warranty Period ◽  
Proposed Model ◽  
The Impact

Purpose The purpose of this paper is to present a decision model for second-hand products to determine the optimal upgrade level, warranty period and preventive maintenance (PM) effort level which maximize the total expected profit generated by the dealer considering any given past age of the product and the effect of the sales volume. Design/methodology/approach A mathematical model is developed to derive the optimal triplet: upgrade level, warranty period and PM effort level, which maximize the total expected profit generated by the dealer for any second-hand product with a given past age. Numerical experimentations have been conducted to investigate the effectiveness of the proposed model and to explore the interactions among the model variables. Findings Numerical experimentations including a sensitivity analysis have been conducted on the model key parameters. The obtained results show that performing PM actions during the warranty period helps the dealers to provide extended warranty for older second-hand products without spending a significant effort on upgrade actions and therefore increase the volume of sales. Also, the interaction between the PM level and the profit margin threshold is demonstrated. Finally, the effect of the sales volume function parameters (the price and warranty elasticity parameters) on the optimal solution is characterized. Research limitations/implications Given the complexity of the profit function to be maximized involving a considerable number of decision variables with different nature, the authors limited the study to the case where the past age of the second-hand product is known. Practical implications The proposed model aims to provide second-hand product dealers with a modeling framework that enables them to have a realistic estimation of the generated profit by integrating the marketing and engineering key parameters of the second-hand product. Originality/value Most of the existing literature dealing with the reliability improvement of second-hand products does not take into account the fact that a realistic estimation of the total profit generated by the dealer requires the consideration of the sales volume. The latter is closely related to the marketing parameters characterized by the warranty period length and the second-hand product selling price. The proposed model introduces the effect of the total sales volume on the total expected profit. The authors also introduce the concept of discrete upgrade levels for a better control of the restoration degree. The authors study the impact of warranty and price elasticity parameters on the optimal solution and the resultant interaction with the customer purchase decision and consequently the sales volume.

scholarly journals Optimizing two-dimensional renewable warranty policies for sensor embedded remanufactured products

2017 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
Ammar Alqahtani ◽  
Surendra M. Gupta
Keyword(s):  
Preventive Maintenance ◽  
Discrete Event ◽  
Two Dimensional ◽  
Experimental Conditions ◽  
Specific Product ◽  
Event Simulation ◽  
Recovery System ◽  
The Cost ◽  
Warranty Policies ◽  
The Impact

Purpose: Remanufactured products, in addition to being environment friendly, are popular with consumers because they can offer the latest technology with lower prices in comparison to brand new products. However, some consumers are hesitant to buy remanufactured products because they are skeptical about the quality of the remanufactured product and thus are unsure of the extent to which the product will render services when compared to a new product. A strategy that remanufacturers may employ to entice customers is to offer warranties on remanufactured products. To that end, this paper studies and scrutinizes the impact of offering renewing warranties on remanufactured products. Specifically, the paper suggests a methodology which simultaneously minimizes the cost incurred by the remanufacturers and maximizes the confidence of the consumers towards buying remanufacturing products.Design/methodology/approach: This study uses discrete-event simulation to optimize the implementation of a two-dimensional renewing warranty policy for remanufactured products. The implementation is illustrated using a specific product recovery system called the Advanced Remanufacturing-To-Order (ARTO) system. The experiments used in the study were designed using Taguchi’s Orthogonal Arrays to represent the entire domain of the recovery system so as to observe the system behavior under various experimental conditions. In order to determine the optimum strategy offered by the remanufacturer, various warranty and preventive maintenance scenarios were analyzed using pairwise t-tests along with one-way analysis of variance (ANOVA) and Tukey pairwise comparisons tests for every scenario.Findings: The proposed methodology is able to simultaneously minimize the cost incurred by the remanufacturer, optimize the warranty price and period, and optimize the preventive maintenance strategy resulting in increased consumer confidence.Originality/value: This is the first study that evaluates in a quantitative and comprehensive manner the potential benefits of offering warranties with preventive maintenance on remanufactured products.

Recognition of Protrusion Defect Fault in Gas Insulated Switchgear Base on SF6 Decomposition Product

2018 ◽  
Vol 8 (1) ◽  
pp. 131
Author(s):  
Visa Musa Ibrahim
Keyword(s):  
Preventive Maintenance ◽  
Decomposition Product ◽  
Partial Discharge ◽  
Sulphur Hexafluoride ◽  
Decomposition Products ◽  
Gas Insulated Switchgear ◽  
Product Method ◽  
Ftir Spectrometer ◽  
Sf6 Decomposition ◽  
The Impact

A solid analytic procedure of Gas insulated switchgear condition checking is utilized in this studies as a part of exploration for the detection of sulphur hexafluoride gas (SF6) decomposition by-product because of its high affectability, reliability and anti-electromagnetic obstruction. This is known as chemical decomposition by-product method. A simulated coaxial deterioration chamber was designed and used on the high voltage electrode to re-enact the decomposition of SF6 under the impact of protrusion defect that generates partial discharge in the coaxial chamber at a pressure of 0.2MPa.The chamber is energised at 50kv for the period of 50 hours and the generated partial discharge simulate the decomposition of SF6 gas. The deterioration decomposition products SO2, SOF2, SO2F2, SO2F10, SiF4, CO, C3F8, C2F6 were detected offline by FTIR spectrometer. These deteriorated items and its concentration can be utilized to recognize and distinguish the type and the magnitude of fault in gas insulated switchgear (protrusion fault) before failure occur for the aim of preventive maintenance.

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