Papers by Keyword: Maintenance

Abstract: According to studies conducted by Information Technology (IT) analysts, the average cost per minute of IT equipment downtime is about $7,900, depending on the sector the company is active in. The average reported incident length is 86 minutes, resulting in average costs per incident of approximately $690,200 . This illustrates that failure in the operation and maintenance of Data Centre (DC) infrastructure has enormous impacts and consequences. Facility Management (FM) in data centres requires a broad and clear understanding of procedures and processes to avoid human errors and to ensure an economic and reliable operation of the clients’ primary activities. In the DC-industry, availability is the most important factor followed by economical aspects. Therefore, both research and implementation of stable processes with an optimal number of interfaces between IT related functions and FM are necessary to increase the effectiveness and efficiency. Therefore, this paper explains the settings of current FM and maintenance concepts used by the DC-industry. Furthermore, the need for a more innovative approach to ensure an economic and reliable operation of DC in the future is introduced. A special emphasis is on a review of the current status and deficits of facility maintenance und management concepts for DC providing direction for future research. It seems that maintenance has developed from an operational, technically-based activity to a strategically important management function.

Abstract: This article addresses the problem of the joint policy of production and maintenance under constraint of outsourcing. The production system considered brings together two companies; the principal represented by a machine Md, while the subcontractor represented by a machine Ms. Our production system aims to satisfy a constant and continuous demand for a single product type. Indeed, outsourcing is justified by the lack of production capacity. However, the main objective is to determine simultaneously for each period, the age of preventive maintenance, the optimal stock threshold level, the maximum capacity of subcontractor and its unit cost of production, to better satisfy the customer's need. The last two parameters encourage an optimal choice of subcontractor, while minimizing the total cost generated by the contractor, including the costs of maintenance, production, storage and shortage. The results show that the proposed model performs quite well and opens new research direction for future improvements.

Abstract: The paper presents, in a synthetic manner. some points of view regarding the necessity of a balanced approach to reliability and engineering risk. It presents some of the risk reduction principles applied in the processes of improving reliability and reducing risk (such as introducing redundancy) and some of the key principles for reducing the risk of failure that can be applied with success. One does have also in view that critical failures in many industries can have disastrous environmental and health consequences. Such failures entail loss of production for very long periods of time and extremely high costs of the intervention for repair. Consequently, for industries characterised by a high cost of failure, setting quantitative reliability requirements must be driven by the cost of failure. Failure rate modelling is relevant for reliability analysis and other disciplines that employ the notion of the failure rate or its equivalents

Abstract: The paper presents representative aspects of the blades and the characterisation of excavator blades, namely frontal loader in the quall resistance to wear version. In exploitation the active surfaces of the blades are subjected to wear through abrasion under high and medium pressure, combined with mechanical fatigue with variable cycles. Retiring the blades is determined by significant degradation of the side zones. The solution developed in order to confront the mentioned phenomena is of modular type, namely equipping the blades with intelligent protection and self-protection systems to wear, which are deposited by cladding with welding on the supports. The blades support is made out of low alloyed steel, which have a controlled hardness and are micro alloyed with boron. The rods used to develop the wear protection systems are type Fe-25%Cr-4%W-Ti-V-La which deposit layers that have a minimum hardness of 55HRC. The challenges solved are related to welding compatibility, in working conditions, of the base materials and the welding ones, through manual electric welding procedure and respective deformation due to residual tensions in the welded structure.

Abstract: Road traffic accidents are challenges the world is battling in recent times. Majority of increasing road fatalities occurs in developing countries. This study seeks to address part of the issues leading to mechanical failures and road traffic accidents in the developing countries with Ghana as a case study. The study model was validated with the use of a sample collected from 880 mechanics from six regions. The mechanics completed questionnaire measures of perception on used parts, brand new parts, mechanical failure, road accidents and demographic variables. In addition, observation and survey method were also used to collect the data on work quality. The result shows that mechanical failure and road traffic accident correlated positively with used parts and negatively correlated with brand new parts. The study model explained R2 = 0.46 and 0.65 of the variance in mechanical failure and road traffic accident respectively. The independent predictors of mechanical failure were age, gender, experience, perception about used parts and work quality. The predictors of road traffic accident were experience, mechanical failure, perception about brand new parts and work quality. We conclude that the mechanical failure and road traffic accidents could be attributed to non-use of genuine parts, poor work quality standard and poor supervision during and after repairs. Remedial measures addressing these issues could reduce road traffic accident in Ghana.

Abstract: This paper investigates technical and organizational tools to improve maintenance planning performances. Indeed, maintaining a high level of reliability and availability of a Medium Voltage electrical network protection system such as the Medium Voltage and High Voltage circuit-breaker and its numerical protection relay at a low operating expenses cost is one of the most critical and challenging tasks for MV electrical distribution network operators. This work has mainly two goals. Firstly, to propose an operating expenses budget function that evaluates the Planned Scheduled Preventive Maintenance Policy combined with a Condition-based maintenance fora real series-parallel multi-assets MV electrical distribution system with active redundancy under the reliability and the maintenance frequency visits of these components. Secondly, to implement an integrated genetic algorithm approach in order to look for the optimal perfect and planned preventive maintenance scheduling policy and condition-based maintenance that minimizes the maximum operating expenses cost of the entire system.The method determines the optimal schedule of preventive maintenance actions based on minimization both reliabilty and operating expenses costs. Conclusions and recommendations for practice are made on the basis of obtained results.

Abstract: Overall Equipment Effectiveness (OEE) of a machine plays a significant role in the present scenario, where right quality and right delivery at the right time are the major factors influencing a customer. The aim of this article is to study the effectiveness and implementing of an independent maintenance system in a machine shop for enhancing OEE with the help of Total Productive Maintenance (TPM) and 5S techniques using a systematic approach. This has been focused to minimize the breakdowns, increase the performance and quality rate of machines so as to improve the effectiveness. During this research discussion, reviewing of documentation and sequential records and direct observations were used as data collection methods. In this case study, increase in efficiency and productivity of machines in terms of OEE by implementing TPM in a machine shop are discussed. This research work deals with the aspects of availability, performance and quality which are used to calculate the OEE of a machine. The TPM techniques such as 5S, preventive maintenance and cleaning were effectively applied on the machine. The final result showed that the OEE improved by 5% in horizontal machining center and by 7% in vertical machining center.

Abstract: Maintenance of buildings is an activity that is carried out to keep away the building from damages in order to continue its function in accordance with the initial planning and design.This study analyzed the characteristics of building maintenance on three public universities in Malang City region; State University of Malang (UM), Islamic University of Malang (UIN Malang), and Polytechnic of Malang (Polinema). The building maintenance includes maintenance of building structures, architecture, and services (mechanical and electrical). This study was aimed to investigate: 1) the maintenance period; 2) the maintenance cost; 3) the maintenance priority; and 4) the correlation among the maintenance period, cost, and priority for each public universities in Malang. The method used is descriptive analysis. The data were obtained from questionnaires given to each university’s maintenance authority.

Abstract: This paper presents overviews about reliability and maintainability of equipment especially for job-shop manufacturing systems. The job shop industry has the characteristics of a more dynamic production than flow shop industries, where products with a variety of great but small amounts. Its dynamic condition certainly contributes directly to the failure rate and reliability growth of equipment. Therefore, proper maintenance should be done as the reliability improvement. Stages of reliability improvement are reliability modeling, reliability analysis and maintenance optimization. This stage is based on reliability growth of equipment that is indicated the deterioration process of failure components, it can be build from maintenance data history or condition data monitoring.. Cost is often considered in points of a maintenance schedule. This cost was affected by minimizing the negative effects of maintenance and maximizing the benefit of production. The attention at reliability and maintenance optimization is a well researches area until now. This paper presents a brief review of existing reliability and maintenance research. Several reliable methods in this area are discussed and maintenance on job-shop industry as future prospects is investigated. It is shown in this paper that some aspect in the area of maintenance on job-shop industry steel needs to be deeply developed.

Abstract: Generally, a maintenance process of a machine tool is oriented to maintain its reliability and availability in a relation of its productivity. This productivity will make a direct impact on the economic aspect of its plant. Ecomaintenance is a maintenance concept which sees maintenance in a different perspective. There is another effect on a machine that is maintained well on the environmental aspect beside its benefit of technology and economic aspects. If a machine is maintained with a proper maintenance, it will have a performance suitable with its age design condition. A machine with a good maintenance generally has a minimum rate of pollutant and waste which is possible emerging from the machining process. Then, if it uses for a machining process, it will produce a good quality product on its surface roughness and dimension accuracy. The electrical energy consumption of the machine also can be saved. It means that the GHG which usually emerges from the process of electrical energy generation in the power plant can be minimized, also the coal as fuel can be saved. The result of experiment has proven that the machine with bad maintenance will consume the electrical power higher in range 10%-60.81% than the machine with a good maintenance.