Reliability-centred maintenance for electric power distribution systems Introduction to Reliability-Centered Maintenance. institutionalizing an RCM. Introduction to Reliability-Centered Maintenance. applies the NASA- created Reliability-Centered Maintenance (RCM) Guide to. PDF | The maintenance function must ensure that all production and manufacturing systems are operating safely and reliably and provide the.
|Language:||English, Spanish, Dutch|
|Genre:||Politics & Laws|
|ePub File Size:||17.70 MB|
|PDF File Size:||11.15 MB|
|Distribution:||Free* [*Sign up for free]|
Reliability-Centered Maintenance (RCM) is the process of determining the Reliability Centered Maintenance originated in the Airline industry in the 's. RCM develops logical decisions based on the following precepts: • The objective of maintenance is to preserve an item's function(s). Maintenance - RCM. • What is Reliability Centered Maintenance? • It is not: – Hardware or Software. – A Type of Maintenance. – A Product that is downloadd.
Context[ edit ] It is generally used to achieve improvements in fields such as the establishment of safe minimum levels of maintenance, changes to operating procedures and strategies and the establishment of capital maintenance regimes and plans. Successful implementation of RCM will lead to increase in cost effectiveness, machine uptime, and a greater understanding of the level of risk that the organization is managing. The late John Moubray, in his book RCM2 characterized reliability-centered maintenance as a process to establish the safe minimum levels of maintenance. This description echoed statements in the Nowlan and Heap report from United Airlines. This starts with the seven questions below, worked through in the order that they are listed: 1. What is the item supposed to do and its associated performance standards?
It is important to identify the occurrences of failure and probability of failure for ranking the failure paths.
It gives information about area of concentration in maintenance activities. The selection is based on the breakdown failures record of past 18 months.
RCM methodology are applied an system failure analysis is done. Preventative maintenance shedule for RCM is prepared and it is compared with the plant maintenance schedule.
It supplies compressed instrument air and service air to the plant. It consists of various components, proper working of which ensures the functions of the compressor unit. Moreover failures of such components cause the shutdown of the compressor unit and hence affect the working of the overall plant.
The maintenance schedule of the company mainly focuses on the daily breaking failures and an overhauling during year.
Therefore this work aims to generate proper maintenance planning and scheduling for the compressor unit that based on the RCM technique for the air compressor unit components. Reliability centered maintenance RCM is the qualitative technique for developing the optimal preventive maintenance program which will ensure inherit ant reliability of machine operation.
RCM can be defined as a process or method used in structured way to determine the most effective approach of preventive maintenance of equipment in its operating condition after proper evaluation of failure consequence. It focuses on the system, function, functional failure, dominant failure effect, their occurrences and critically.
RCM philosophy employs preventive maintenance, predictive maintenance PDM , time directed TD , condition directed CD , failure finding FF and run-to-failure RTF maintenance techniques in an integrated manner to increase the probability that a machine or component will function in the required manner over its design life cycle with a minimum of maintenance.
This paper contains the RCM methodology and its implementation in an air compressor unit, key points in RCM maintenance plan. Afefy The results of the RCM technique applied of the plant show that the PM proposed tasks and planning are generated. Moreover, PM is consisted of on-condition and scheduled maintenance.
The analysis forms the basis for the development of quantitative models for maintenance strategy selection and optimization. The mathematical models for maintenance strategy selection and optimization that are being developed based on the presented RCM study aim at contributing to this process. It is concluded to be an important step in order to enhance the reliability, availability and profitability of wind turbines.
Study made by Salman T. Al-Mishari, and S. Assessment of contributing factors is often based on very subjective judgment. Shifts and drifts often occur. The work reported in this paper attempts to illustrate the potential losses of missing these important elements through a real example.
The RCM has been used to analyze and perform a decision making process in which maintenance strategy needs to be chosen depends on the criticality of the equipment to the organization. System boundary definition. Step 3: Step 4: Step 5: Step 7: Task Selection. Satisfactory completion of these seven steps will provide the preferred PM tasks.
Failures in air compressor unit is selected for the RCM study and the relevant information is collected from the company.
The functional block diagram for system is shown in fig. Failure mode and effect analysis FMEA for different subsystems are done then the criticality and probability of occurrences for the various failures are calculated and categorized in four groups as shown in table no.
RCM task is selected.
RCM Schedule: Inspect chock up of valve F. Monthly delivery valve high failure rate component. Inspect fracture components. Periodic cleaning of a Air suction filter. Replace of lapping. Piston Ring Road Piston ring Moderate cost, high 1. Check for suction pressure C. Check for suction pressure high, low.
Check for piston ring every 6 months Guide ring Moderate Cost, high 1. Check for piston ring every 6 months. Other piston Low failure rate 1. Keep one H.
Check guide ring every 6 month 3. Lubrication i. Oil leakage failure failure parts gaskets iii. Belt Belt High cost, moderate i. Tighting of C. Condition of failure belts belts ii. Keep match RTF sets of belts 7. Packing 1. Suction filter All suction filter Moderate cost, low 1. Cleaning of suction filter C. RCM can be used to create a cost-effective maintenance strategy to address dominant causes of equipment failure.
It is a systematic approach to defining a routine maintenance program composed of cost-effective tasks that preserve important functions. The important functions of a piece of equipment to preserve with routine maintenance are identified, their dominant failure modes and causes determined and the consequences of failure ascertained.
Levels of criticality are assigned to the consequences of failure. Some functions are not critical and are left to "run to failure" while other functions must be preserved at all cost.
Maintenance tasks are selected that address the dominant failure causes.
This process directly addresses maintenance preventable failures. Failures caused by unlikely events, non-predictable acts of nature, etc. When the risk of such failures is very high, RCM encourages and sometimes mandates the user to consider changing something which will reduce the risk to a tolerable level. The result is a maintenance program that focuses scarce economic resources on those items that would cause the most disruption if they were to fail.
RCM emphasizes the use of predictive maintenance PdM techniques in addition to traditional preventive measures. Background[ edit ] The term "reliability-centered maintenance" was first used in public papers  authored by Tom Matteson , Stanley Nowlan , Howard Heap , and other senior executives and engineers at United Airlines UAL to describe a process used to determine the optimum maintenance requirements for aircraft.
Having left United Airlines to pursue a consulting career a few months before the publication of the final Nowlan-Heap report, Matteson received no authorial credit for the work. However, his contributions were substantial and perhaps indispensable to the document as a whole. They brought RCM concepts to the attention of a wider audience.
The first generation of jet aircraft had a crash rate that would be considered highly alarming today, and both the Federal Aviation Administration FAA and the airlines' senior management felt strong pressure to improve matters. In the early s, with FAA approval the airlines began to conduct a series of intensive engineering studies on in-service aircraft.
The studies proved that the fundamental assumption of design engineers and maintenance planners—that every airplane and every major component in the airplane such as its engines had a specific "lifetime" of reliable service, after which it had to be replaced or overhauled in order to prevent failures—was wrong in nearly every specific example in a complex modern jet airliner. This was one of many astounding discoveries that have revolutionized the managerial discipline of physical asset management and have been at the base of many developments since this seminal work was published.
Among some of the paradigm shifts inspired by RCM were: an understanding that the vast majority of failures are not necessarily linked to the age of the asset changing from efforts to predict life expectancies to trying to manage the process of failure an understanding of the difference between the requirements of assets from a user perspective, and the design reliability of the asset an understanding of the importance of managing assets on condition often referred to as condition monitoring, condition based maintenance and predictive maintenance an understanding of four basic routine maintenance tasks linking levels of tolerable risk to maintenance strategy development Today RCM is defined in the standard SAE JA, Evaluation Criteria for Reliability-Centered Maintenance RCM Processes.
This sets out the minimum criteria for what is, and for what is not, able to be defined as RCM. The standard is a watershed event in the ongoing evolution of the discipline of physical asset management. Prior to the development of the standard many processes were labeled as RCM even though they were not true to the intentions and the principles in the original report that defined the term publicly.
Today companies can use this standard to ensure that the processes, services and software they download and implement conforms with what is defined as RCM, ensuring the best possibility of achieving the many benefits attributable to rigorous application of RCM.
Modern RCM gives threats to the environment a separate classification, though most forms manage them in the same way as threats to safety. RCM offers five principal options among the risk management strategies: Predictive maintenance tasks, Preventive Restoration or Preventive Replacement maintenance tasks, Detective maintenance tasks, Run-to-Failure, and One-time changes to the "system" changes to hardware design, to operations, or to other things.
RCM also offers specific criteria to use when selecting a risk management strategy for a system that presents a specific risk when it fails. Some are technical in nature can the proposed task detect the condition it needs to detect?
Others are goal-oriented is it reasonably likely that the proposed task-and-task-frequency will reduce the risk to a tolerable level?