Sharif Digital Repository

Application of Reliability Centered Maintenance (RCM) in a system results in a decrease in component failure rates and as such improvement in the system reliability. One of the major subjects of the RCM is focused on the Online and Offline Preventive Maintenance (OPM and FPM which together will be denoted by OFPM) of the components which repairing the component needs or doesn't need to stop the mission carrying out by it. The RCM is classified as a preventive maintenance policy and has significant contribution in practical applications. However, little research has been devoted to modeling the online and offline Preventive Maintenance. This research assumes that the component failure rate... 

The aim of this two-part paper is to present a comprehensive reliability-centerd maintenance framework tailored to power distribution systems. The first paper discusses the fundamental concepts, presents the developed algorithm, and introduces the required mathematical formulations. This second paper is focused on the application of the proposed methodology on a real distribution system. Considerable effort is devoted to examine the proposed method in a step-by-step manner to clarify the implementation procedure. The required data for the procedure are taken from available references and follow reasonable technical assumptions. Practical aspects are incorporated, and the results obtained are... 

Historically, most of the maintenance tasks in rolling stock companies are devoted to Preventive Maintenance which leads to some problems such as erroneous maintenance work, unnecessary maintenance tasks, etc. Therefore, it is essential to develop effective maintenance strategies to deal with these problems. While the safety is a significant factor in rolling stock industries, the most well known and widely applied maintenance optimization strategy is so called Reliability Centered Maintenance (RCM). The aim of this paper is to discuss the implementation of RCM to make maintenance of rolling stock of the Raja Passenger Train Corporation more cost effective. Therefore, the paper presents RCM... 

Although reliability-centered maintenance (RCM) has proven its noticeable merits in many industries, has not been yet furnished with efficient analytical methods in the power engineering context. The first of this two-paper set presents a practical framework by which the RCM procedure can be implemented in power distribution systems. The proposed algorithm consists of three main stages. The prerequisites of the analysis are outlined in the first stage. In the second stage, an approach is developed to identify the network's critical components, from the reliability point of view. Having practically modeled the components' failure rates, an efficient cost/benefit evaluation approach is then... 

This paper presents a dynamic programming methodology for finding the optimum preventive maintenance schedule of generating units of a GENCO in open power systems. The objective function for the GENCO is to sell electricity as much as possible, according to the market price forecast. Various constraints such as generation capacity, duration of maintenance and maintenance crew are taken into account. In a case study, introducing a GENCO with six generating units, and implementing dynamic programming, we obtain the optimal maintenance schedule over the planning period. © 2002 IEEE  

The proper and reliable operation of circuit breakers (CBs) directly affects the reliability and continuity of electricity services in a power systems. Condition-based maintenance (CBM) is the best economic CB maintenance strategy through its online monitoring (OLM) possibilities. Since there is a large number of CBs in a power system, to equip all CBs with OLM systems is not economically justifiable however. This paper, as the second part of a two-part paper, presents an effective optimization framework to find the optimal number of CBs to be monitored online as the kernel of CBM process. To prove its feasibility, the proposed approach is applied to the IEEE Roy Billinton Test System, which... 

This paper presents the most frequently used maintenance concerns and challenges in distribution utilities of Iran. A questionnaire is devised and distributed among the maintenance experts in more than 30 distribution utilities all over Iran and their responses have been taken under consideration in this paper. The aim is to get the most out of the successful maintenance experiences within the utilities, to find the solutions on the current common challenges on the distribution system maintenance policies, and eventually to enlighten the way on the transition to the more efficient maintenance approaches such as reliability-centered maintenance (RCM) in distribution systems  

This paper presents the most frequently used maintenance concerns and challenges in distribution utilities of Iran. A questionnaire is devised and distributed among the maintenance experts in more than 30 distribution utilities all over Iran and their responses have been taken under consideration in this paper. The aim is to get the most out of the successful maintenance experiences within the utilities, to find the solutions on the current common challenges on the distribution system maintenance policies, and eventually to enlighten the way on the transition to the more efficient maintenance approaches such as reliability-centered maintenance (RCM) in distribution systems  

Recognition of the circuit-breaker's (CB) vital role in reliable operation and protection of power systems (i.e., during energization, disconnecting loads, and clearing faults), helps to understand the requirement and importance of its maintenance management as well as maintenance scheduling. Condition-based maintenance (CBM), employing online monitoring (OLM) of CBs, has been long reported as the most practical maintenance policy on the power system CBs. There are a large number of CBs in a power system to be monitored; however, to address the financial limitations for OLM implementation (in utilities), a method will be proposed to find the most critical breakers for enforcing effectively... 

The emergence of smart grid technologies in terms of advanced communication infrastructure, embedded intelligence, diagnostics and monitoring capabilities offers new opportunities for improved transmission asset management strategies (TAMS). Accordingly, power system operators are currently looking for analytics that can make use of transmission asset condition monitors and data already available to make better-informed decisions. This two-part paper introduces a two-stage maintenance scheduler for power transmission assets. Part I begins with the motivation for TAMS and then continues with a two-stage maintenance management model that incorporates joint midterm and short-term maintenance.... 

Update of software usually equates disruption to a program's execution. However, such disruptions in the execution of applications that provide round-the-clock services is not desirable. Examples of such applications include multi-tier enterprise systems with which users may interact via distinct presentation tiers at the same time. Existing software updating systems do not operate in the enterprise applications, or they need most of the redeployment tasks to be performed manually. In this paper, we present a framework capable of Automatically Redeploying Enterprise Software Applications (ARESA). This system combines the idea of incremental and integral updates to preserve the consistency of... 

With the rapid evolution of electricity markets and the need for higher economic efficiency of power industry, attempts for lowering down the maintenance costs as a large portion of system operation expenses seem imperative. Recognised as a crucial step in practical implementation of modern maintenance paradigms, e.g. reliability-centred maintenance, this study proposes an efficient method to quantify the generating units' criticality on the bulk power system reliability performance. The proposed approach utilises a solution concept of game theory and evaluates the contribution of each generating unit on the overall system reliability when a higher-order contingency occurs. The suggested... 

In this paper resilience oriented water and energy hub scheduling for a remote area is presented. The optimal operation scheduling considering maintenance programming and reliability indices are presented. Demands which include electricity, heat and drinking waters are supplied by diesel generators, boilers, combined heat and power units, and drinking water sources such as desalination units and transferring water. The considered system contains renewable energy resources such as wind turbine and photovoltaic arrays as well as electrical storage units. In order to enhance resiliency of system against forced outages of components and regular maintenance programs, maintenance constraints and... 

Achievement of industries in production and offering products depends on different factors like having an appropriate maintenance system. This issue should be reached through the most appropriate and practical methods. In this study, based on how the external parameters would influence the productivity of a maintenance system the researcher aims at designing a dynamic system model to analyze the productivity of a maintenance system using acquired information from a car device company by determination of the percentage of parameters and indexes and their influence on maintenance system productivity. The proposed model is simulated for a system with parameters of precise value according to... 

The study explores language maintenance and shift patterns from a family language policy perspective in Azerbaijani-Farsi bilingual families in the City of Zanjan, Iran. The city is the capital of Zanjan province which is surrounded by Azerbaijani, Kurdish, and Farsi speaking provinces giving it a specific demographic make-up to explore language maintenance and shift processes from a family language policy perspective. Thirteen parents (six fathers and seven mothers) from upper, middle, and lower socioeconomic statuses were interviewed about their language ideologies, practices, and management with respect to the maintenance of their ethnic language, Azerbaijani, and the official language of... 

In maintenance and replacement planning of an industry, the purchasing of new equipment on the market with some kind of technological improvement over existing equipment should be taken into account. Because of operating cost, ordinary and preventive maintenance expenses may be lower, production rate may be higher and the quality of output may be better, etc. The industry to be considered in this paper is the mining industry and the replaced equipment is the mine shovel. It is assumed that, at most, one new shovel can be purchased before the mine is exhausted. It is possible that the mine is given up before exhausted, because of the disadvantage of the expense and loss of the salvage value... 

This paper deals with the problem of scheduling bus maintenance activities. The scheduling of maintenance activities is an important component in bus transit operations planning process. The other components include network route design, setting timetables, scheduling vehicles, and assignment of drivers. This paper presents a mathematical programming approach to the problem. This approach takes as input a given daily operating schedule for all buses assigned to a depot along with available maintenance resources. It, then, attempts to design daily inspection and maintenance schedules for the buses that are due for inspection so as to minimize the interruptions in the daily bus operating... 

This paper develops a reliability-based model for distribution network expansion planning (DNEP) studies. It incorporates the effects of distribution line maintenance in the planning studies to be considered as an alternative for the installation of feeders. To that end, at first, some models are introduced to effectively estimate the effects of maintenance activities budget on distribution lines' failure and repair rates. Therefore, the reliability data of distribution lines are updated in the reliability evaluation studies of distribution networks. Then, these models are involved in the formulation of DNEP problem which is introduced as a multi-objective optimization model. The developed... 

Wheel wear is one of the major costs in railway tracks consisting of sharp curves. In this paper, wear behavior of S1002 profiles of wheels in the "Southern Line" of Iran's railway, which consists of a large number of distinct and/or consecutive sharp curves, is studied using the field data measuring technique. Based on wear behavior analysis of all wheels, an optimal wagon maintenance technique called the "first and second limits" is suggested to minimize the wagon's cost per traveled distance. The results show that: 1) A severe wheel flange wear occurs for all wheels in comparison to the wheel tread wear in normal tracks; 2) A wagon's detachment for repair of critical wheels on its four...