Reducing the Cost of Tea Production through Employing Usage Based Preventive Maintenance (Case Study in Kenya Tea Development Agency Factory KTDA Chebut)

2021 ◽  
Author(s):  
Benard Kipsang ◽  
Kiprotich Evans
Keyword(s):  
Preventive Maintenance ◽  
Development Agency ◽  
Tea Production ◽  
The Cost

scholarly journals Preventive maintenance of multiple components for hydraulic tension systems

2021 ◽  
Vol 23 (3) ◽  
pp. 489-497
Author(s):  
Hongyan Dui ◽  
Xiaoqian Zheng ◽  
Qian Qian Zhao ◽  
Yining Fang
Keyword(s):  
Working Conditions ◽  
Preventive Maintenance ◽  
Conveyor Belt ◽  
Tension Force ◽  
Maintenance Cost ◽  
Number Of Components ◽  
Multiple Components ◽  
Conveyor Belts ◽  
The Cost

Automatically controlled hydraulic tension systems adjust the tension force of a conveyor belt under different working conditions. Failures of an automatically controlled hydraulic tension system influence the performance of conveyor belts. At present, the maintenance of automatically controlled hydraulic tension systems mainly considers the replacement of components when failures occur. Considering the maintenance cost and downtime, it is impossible to repair all the failed components to improve the hydraulic tension system. One of the key problems is selecting the most valuable components for preventive maintenance. In this paper, preventive maintenance for multiple components in a hydraulic tension system is analyzed. An index is proposed to select more reliable preventive maintenance components to replace the original ones. A case study is given to demonstrate the proposed method. When the cost budget increases, there are three different variations in the number of components for selective preventive maintenance (SPM).

Developing Schedule With Linear Programming (Case Study: STTF II Project Komplek Sukamukti Banjaran)

2020 ◽  
Vol 4 (02) ◽  
pp. 34-45
Author(s):  
Naufal Dzikri Afifi ◽  
Ika Arum Puspita ◽  
Mohammad Deni Akbar
Keyword(s):  
Linear Programming ◽  
Objective Function ◽  
Project Scheduling ◽  
Time Limit ◽  
Minimum Time ◽  
Service Cost ◽  
Trade Off ◽  
Overtime Work ◽  
The Cost

Shift to The Front II Komplek Sukamukti Banjaran Project is one of the projects implemented by one of the companies engaged in telecommunications. In its implementation, each project including Shift to The Front II Komplek Sukamukti Banjaran has a time limit specified in the contract. Project scheduling is an important role in predicting both the cost and time in a project. Every project should be able to complete the project before or just in the time specified in the contract. Delay in a project can be anticipated by accelerating the duration of completion by using the crashing method with the application of linear programming. Linear programming will help iteration in the calculation of crashing because if linear programming not used, iteration will be repeated. The objective function in this scheduling is to minimize the cost. This study aims to find a trade-off between the costs and the minimum time expected to complete this project. The acceleration of the duration of this study was carried out using the addition of 4 hours of overtime work, 3 hours of overtime work, 2 hours of overtime work, and 1 hour of overtime work. The normal time for this project is 35 days with a service fee of Rp. 52,335,690. From the results of the crashing analysis, the alternative chosen is to add 1 hour of overtime to 34 days with a total service cost of Rp. 52,375,492. This acceleration will affect the entire project because there are 33 different locations worked on Shift to The Front II and if all these locations can be accelerated then the duration of completion of the entire project will be effective

Perancangan dan Pembuatan Alat Bantu Meja Putar untuk Mesin Cnc 4 Axis

2016 ◽  
Vol 10 (2) ◽  
pp. 162-171
Author(s):  
Hafid Hafid ◽  
Tatang Sutisna
Keyword(s):  
Processing Time ◽  
Rotary Table ◽  
Engineering Process ◽  
Cnc Machine ◽  
Economical Analysis ◽  
Machining Center ◽  
Design And Manufacturing ◽  
The Cost ◽  
Productivity And Competitiveness

The design and manufacturing of the rotary table with the specification Ø 170 mm (6 inches) for CNC machine 4 axis has been done. The objective of manufacturing a rotary table is to increase the efficiency of CNC machine Hardford 4 axis to be above 80% in line machining center CV. IM’s workshop. The engineering methods was taken, consist of: working preparation, manufacturing of working drawing, engineering process, the manufacturing and testing. The prototype has been tested and operated, the resulting of increasing productivity of which were as follows: the process of assembling was increased to be 3 time ( before 1 time) and processing time for a specific case reduced from 5 hours to 3 hours, number of operators for the case of assembling the rotary reduced to 1 person (before 4 persons), safety and security become to be better. The results show increased efficiency of CNC machine Hardford, from under 50% to be above 80%. Based on the economical analysis obtained by the cost of good sold (C.G.S) of the rotary table is IDR 34.060.000. The results presented in this paper is expected to be case study for developing a business of the metal and engineering SMEs domestic to the effort of improving efficiency, quality, productivity and competitiveness in global market.ABSTRAKPerancangan dan pembuatan alat bantu meja putar (rotary table) dengan spesifikasi teknis Ø 170 mm (6 inci) untuk mesin CNC 4 axis telah dilakukan. Tujuan pembuatan rotary table adalah untuk meningkatkan efisiensi mesin CNC Hardford 4 axis di atas 80% pada line machining center Bengkel CV. IM. Metode rancang bangun yang dilakukan, meliputi: persiapan kerja, pembuatan gambar kerja, proses engineering, pembuatan dan uji coba. Prototip tersebut telah diuji coba dan dioperasikan dengan hasil peningkatan produktivitas sebagai berikut: proses pengerjaan bongkar pasang meningkat menjadi 3 kali (sebelumnya 1 kali) dan waktu pengerjaan untuk kasus tertentu berkurang dari 5 jam menjadi 3 jam, jumlah operator untuk kasus bongkar pasang rotary berkurang menjadi 1 orang (sebelumnya 4 orang), keselamatan kerja dan keamanan menjadi lebih baik. Hasil peningkatan berupa efisiensi mesin CNC Hardford 4 axis dari sebelumnya di bawah 50% menjadi di atas 80%. Berdasarkan hasil perhitungan analisis ekonomi diperoleh harga pokok produksi (HPP) alat bantu meja putar adalah sebesar Rp. 34.060.000. Bahasan ini diharapkan menjadi contoh kasus bagi pengembangan usaha IKM logam dan mesin dalam negeri untuk meningkatkan efisiensi, mutu, produktivitas dan keunggulan daya saing di pasar global.Kata kunci: alat bantu meja putar, mesin CNC, harga pokok produksi

Case Study—Failure Analysis of a Multiplexer

2016 ◽  
Author(s):  
Michael Woo ◽  
Marcos Campos ◽  
Luigi Aranda
Keyword(s):  
Failure Analysis ◽  
High Reliability ◽  
Component Failure ◽  
Root Cause ◽  
Knowing That ◽  
Cause Of Failure ◽  
The Cost

Abstract A component failure has the potential to significantly impact the cost, manufacturing schedule, and/or the perceived reliability of a system, especially if the root cause of the failure is not known. A failure analysis is often key to mitigating the effects of a componentlevel failure to a customer or a system; minimizing schedule slips, minimizing related accrued costs to the customer, and allowing for the completion of the system with confidence that the reliability of the product had not been compromised. This case study will show how a detailed and systemic failure analysis was able to determine the exact cause of failure of a multiplexer in a high-reliability system, which allowed the manufacturer to confidently proceed with production knowing that the failure was not a systemic issue, but rather that it was a random “one time” event.

The Concept of the Optimum Alignment of Discharge Pipelines Due to the Minimization of the Wave Forces

1992 ◽  
Vol 25 (9) ◽  
pp. 211-216
Author(s):  
A. Akyarli ◽  
Y. Arisoy
Keyword(s):  
Wave Height ◽  
Wave Force ◽  
Wave Forces ◽  
Wave Direction ◽  
Incoming Wave ◽  
Pipeline Route ◽  
Optimum Alignment ◽  
The Cost ◽  
Resultant Wave

As the wave forces are the function of the wave height, period and the angle between the incoming wave direction and the axis of the discharge pipeline, the resultant wave force is directly related to the alignment of the pipeline. In this paper, a method is explained to determine an optimum pipeline route for which the resultant wave force becomes minimum and hence, the cost of the constructive measures may decrease. Also, the application of this method is submitted through a case study.

Neither Victors nor Victims

2017 ◽  
Author(s):  
David Whetham
Keyword(s):  
First Century ◽  
National Interests ◽  
Civil Military Relations ◽  
High Street ◽  
National Survival ◽  
The Uk ◽  
Military Relations ◽  
The Cost ◽  
Realistic Goal

Between 2007 and 2011, Wootton Bassett, a small Wiltshire town in the UK, became the focus of national attention as its residents responded to the regular repatriations of dead soldiers through its High Street. The town’s response came to symbolize the way that broader attitudes developed and changed over that period. As such, it is a fascinating case study in civil–military relations in the twenty-first century. Success may be the same as victory, but victory, at least as it has been traditionally understood, is not a realistic goal in many types of contemporary conflict. Discretionary wars—conflicts in which national survival is not an issue and even vital national interests may not be at stake—pose particular challenges for any government which does not explain why the cost being paid in blood and treasure is ‘worth it’.

scholarly journals Game-Theoretic Decision Support for Cyber Forensic Investigations

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5300
Author(s):  
Antonia Nisioti ◽  
George Loukas ◽  
Stefan Rass ◽  
Emmanouil Panaousis
Keyword(s):  
Cyber Security ◽  
Strategic Decisions ◽  
Bayesian Games ◽  
Bayesian Game ◽  
Cyber Forensics ◽  
Detection And Attribution ◽  
Different Types ◽  
Game Theoretic ◽  
The Cost

The use of anti-forensic techniques is a very common practice that stealthy adversaries may deploy to minimise their traces and make the investigation of an incident harder by evading detection and attribution. In this paper, we study the interaction between a cyber forensic Investigator and a strategic Attacker using a game-theoretic framework. This is based on a Bayesian game of incomplete information played on a multi-host cyber forensics investigation graph of actions traversed by both players. The edges of the graph represent players’ actions across different hosts in a network. In alignment with the concept of Bayesian games, we define two Attacker types to represent their ability of deploying anti-forensic techniques to conceal their activities. In this way, our model allows the Investigator to identify the optimal investigating policy taking into consideration the cost and impact of the available actions, while coping with the uncertainty of the Attacker’s type and strategic decisions. To evaluate our model, we construct a realistic case study based on threat reports and data extracted from the MITRE ATT&CK STIX repository, Common Vulnerability Scoring System (CVSS), and interviews with cyber-security practitioners. We use the case study to compare the performance of the proposed method against two other investigative methods and three different types of Attackers.

Optimizing preventive maintenance over a finite planning horizon in a semi-Markov framework

2020 ◽  
Author(s):  
Antonio Sánchez Herguedas ◽  
Adolfo Crespo Márquez ◽  
Francisco Rodrigo Muñoz
Keyword(s):  
Preventive Maintenance ◽  
Recurrence Relations ◽  
Direct Calculation ◽  
Planning Horizon ◽  
Practical Implementation ◽  
Practical Application ◽  
Mathematical Solution ◽  
Accumulated Reward ◽  
Finite Planning Horizon

Abstract This paper describes the optimization of preventive maintenance (PM) over a finite planning horizon in a semi-Markov framework. In this framework, the asset may be operating, and providing income for the asset owner, or not operating and undergoing PM, or not operating and undergoing corrective maintenance following failure. PM is triggered when the asset has been operating for τ time units. A number m of transitions specifies the finite horizon. This system is described with a set of recurrence relations, and their z-transform is used to determine the value of τ that maximizes the average accumulated reward over the horizon. We study under what conditions a solution can be found, and for those specific cases the solution τ* is calculated. Despite the complexity of the mathematical solution, the result obtained allows the analyst to provide a quick and easy-to-use tool for practical application in many real-world cases. To demonstrate this, the method has been implemented for a case study, and its accuracy and practical implementation were tested using Monte Carlo simulation and direct calculation.

scholarly journals Thermal Efficiency and Economics of a Boil-Off Hydrogen Re-Liquefaction System Considering the Energy Efficiency Design Index for Liquid Hydrogen Carriers

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4566
Author(s):  
Minsoo Choi ◽  
Wongwan Jung ◽  
Sanghyuk Lee ◽  
Taehwan Joung ◽  
Daejun Chang
Keyword(s):  
Flow Rate ◽  
Life Cycle Cost ◽  
Specific Energy Consumption ◽  
Liquid Hydrogen ◽  
Efficient Design ◽  
Fuel Cell Stack ◽  
Energy Efficiency Design Index ◽  
The Cost ◽  
Large Flow

This study analyzes the thermodynamic, economic, and regulatory aspects of boil-off hydrogen (BOH) in liquid hydrogen (LH2) carriers that can be re-liquefied using a proposed re-liquefaction system or used as fuel in a fuel cell stack. Five LH2 carriers sailing between two designated ports are considered in a case study. The specific energy consumption of the proposed re-liquefaction system varies from 8.22 to 10.80 kWh/kg as the re-liquefaction-to-generation fraction (R/G fraction) is varied. The economic evaluation results show that the cost of re-liquefaction decreases as the re-liquefied flow rate increases and converges to 1.5 $/kg at an adequately large flow rate. Three energy efficient design index (EEDI) candidates are proposed to determine feasible R/G fractions: an EEDI equivalent to that of LNG carriers, an EEDI that considers the energy density of LH2, and no EEDI restrictions. The first EEDI candidate is so strict that the majority of the BOH should be used as fuel. In the case of the second EEDI candidate, the permittable R/G fraction is between 25% and 33%. If the EEDI is not applied for LH2 carriers, as in the third candidate, the specific life-cycle cost decreases to 67% compared with the first EEDI regulation.

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