One of the first, yet hardest, things to learn by kevin clark, cmrp. Once youve gathered data on historical equipment failure within the context of the preventive work youre doing, failure modes start to emerge. A maintenance professional can reduce the number of preventive maintenance tasks by scheduling them based on historical data showing when the particular asset tends to fail. W hen looking at the pf reliability curve, there are two main categories of maintenance reliability action where resources may be focused.
Explore lm6000 maintenance solutions multiyear agreements our tailored strategic fleet360 multiyear agreements mya are designed to help you focus on your core business, delivering productive outcomes including plant profitability, competitiveness on the dispatch curve for utilities, and longterm reliability for industrial sites. The pf curve is a useful visual tool that helps maintenance teams make important decisions on how and when to address asset problems. Equation 10 expresses the maintenance cost of an item relative to a unit of its usage. This report was approved for public release on december 29, 1978. Cmms software is essential here, as it allows you to look back at work order history, failure data, and your maintenance schedule.
Oncondition maintenance relies on the capability to detect failures before they happen so that preventive maintenance can be initiated. There is a sense in which failure is a process, not an event. Conditionbased maintenance cbm uses sensor devices to collect realtime measurements ie. Understanding the pf curve and its impact on reliability. For example, the pf curve for a bearing in a particular application may be 6 weeks. How to use the pf curve to improve equipment maintenance and. Examples of pf intervals listed below are some examples to illustrate the application of the pf interval. How to apply the correct maintenance strategy to your assets. Improve preventive maintenance with a pf curve software advice. The pf curve, representing the life of an asset, is elongated when conditionbased maintenance replaces timebased maintenance. In other words, it predicts the condition of an asset based on what usually causes it to fail and when. An introduction to the fundamental concept of the pf curve where we can identify the point of functional failure what the user wants it to do. The maintenance crews are told to make sure their pms are completed within the month so they can meet 100% pm compliance.
Pf curve explained everything you need to know upkeep. But with more and more equipment being fitted with realtime asset health monitoring equipment and with the advent of predictive analytics and big data, is it really relevant anymore. As a maintenance professional, unless you have been sleeping under a rock these last ten or so years, you will have at least heard of the pf curve, even if you dont understand it, or use it to your advantage. Making preventive maintenance tasks more efficient by scheduling them justintime. Logic tells us that the longer the warning period, the easier it is to support the planning and scheduling effort necessary for an efficient, reliabilitybased maintenance organization. After a refactoring maintenance, the original test software can be reused without modification.
You may order this book through this website by clicking here. Nov 01, 20 this problem is made worse when an organization uses maintenance software or eam enterprise asset management software that kicks out all pms for the month on the 1st and you think you have 30 days to complete the pms. The reliability impact within the pf curve by randy riddell w hen looking at the pf reliability curve, there are two main categories of maintenance reliability action where resources may be focused. Reliable process solutions wants to ensure attendees learn effective work management, reliability strategy, precision maintenance, lubrication. Roi work order generator privacy terms become a partner. Functional failure f is a bearing seazing in a fan motor and causing the fan to stop.
The one we show is an iteration refined by preston ingalls, a maintenance consultant with decades of experience in heavy. In the same way your pair of shoes eventually get worn out after 500 miles of walking, your key. The pf curve is a way of representing an assets behavior or condition before it has reached a failed state. At a recent maintenance function, i asked 70 maintenance and reliability professionals how many of them had heard of the pf curve and only about 10% stated they had. What is often not discussed and overlooked, is what happens before the. Maintenance based on the equipment performance monitoring and the control of the corrective actions taken as a result. Pf interval pf curve the ins and outs of maintenance. This post will contrast reliability centered maintenance rcm and condition based maintenance cbm.
By combining design innovations, materials advancements, and proven modelbased control software, the advanced gas path enables ge gas turbine customres to benefit from dramatic output and efficiency improvements, while extending maintenance intervals and maintaining low. Outside of the technical jargon, the scurve model simply makes use of the projected number of manhours and costs to complete the project vs. The curve shows that as a failure starts manifesting, the equipment deteriorates to the point at which it can possibly be detected p. Introduction to reliability centered maintenance rcm part 1. Preventive maintenance of fiber optic cables and optics. Software for growth curve fitting and visualization curve fitter is a program that allows you to fit a growth curve using a simple gui or an advanced scripting environment. Understanding the pf curve and its impact on reliability centered. Some individual units will fail relatively early infant mortality failures, others we hope most will last until wearout, and some will fail during the. How to use the pf curve to improve equipment maintenance.
Pm systems must be designed for the actual equipment as set up, age of the equipment, product, type of. Equation 10 can be solved numerically for the value of t p which minimizes the cost of maintenance in the long term. What is often not discussed and overlooked, is what happens before the equipment starts to deteriorate. Jun 17, 2016 the pf curve can be used to aid in a few important maintenance processes, such as. Jul 17, 2019 the pf curve, representing the life of an asset, is elongated when conditionbased maintenance replaces timebased maintenance. Improving maintenance by adopting a pf curve methodology the pf curve. The goal is to have enough advance notice that we can effectively plan and schedule the repair, get the materials and execute the repair prior to failure. The pf curve chart is the path to a reliable and safe maintenance plan for machinery. In addition to implementing a variety of curve fitting routines its main advantage over other software programs is its ability to allow you to easily visualize your data.
When i see a pf curve with preventive maintenance, and runtofailure strategies combined into it or overlaid on top of it, i realize people do not understand the true meaning of the pf curve. You can think of this problem as a variant of the well known telephone game, where some trivial rumor is repeated from one person to the next until it has become distorted beyond recognition and blown up out of all proportion. If you prefer us to manually process your order or would like to mail or fax order in, please click cd and book order form on our secure servers. After purchase, you receive an email with download link. Jul 11, 2016 there are numerous computerbased maintenance tracking systems or maintenance modules on enterprise software systems you can use to avoid the kinds of oversights and mistakes inherent in paper.
This seminar will work to build upon and assist companies on proper and. Maximizing the pf interval for successful predictive maintenance. You can just copy the system from the manual or from your old job and it will work. There are numerous computerbased maintenance tracking systems or maintenance. Reactive maintenance rm rm, sometimes referred to as living life at the bottom of the pf curve, is maintenance performed after a failure, or after an obvious, unforeseen threat of immediate failure. The curve of figure 1, therefore, looses its simple geometrical visuality. A common misunderstanding about reliability centered maintenance. Maintenance management powerpoint presentation download. The proposed time, manhour and cost data are referred to as the baseline data. The pf curve chart is one of the most important tools for a reliability centered maintenance plan.
The pf curve figure 1 is a common way to represent the. It demonstrates the relationship between machine breakdown, cost, and how it can be prevented. Oncondition maintenance relies on the capability to detect failures before they. Despite its usefulness a lot of companies may overlook its value.
Five tips for optimizing a facility preventive maintenance. Outside of the technical jargon, the s curve model simply makes use of the projected number of manhours and costs to complete the project vs. The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, governmental, and residential installations. Why people do not understand the pf curve by ricky smith cmrp why do people not understand the pf curve. Machines are never built to run forever, but they can last a lot longer than one may expect. Automated download system is powered by our preferred method of payment, secure pay pal. The pf curve is something that wethose of us in the maintenance and. The video also touches on the topics of breakdown, scheduledpreventive. The real actual equipment condition is continuously assessed by the online detection of significant working device parameters and their automatic comparison with average values and performance.
If the failure is not detected and mitigated, it continues until a hard failure occurs f. Oncondition maintenance using pf interval or failure detection. A common misunderstanding about reliability centred. Determining the frequency of condition monitoring tasks. Reliability centred maintenance rcm was developed by the aircraft industry and it has now migrated into industries. Dec 05, 2018 the bathtub curve is used in reliability, engineering and maintenance industries to describe failure rates over time. The f distribution with df1 n1 and df2 n2 degrees of freedom has density. Sample files are included and must be used for demo mode. Planning and scheduling with the pf curve the basics of the pf curve when talking about the pf curve, we must go back to the reliabilitycentered maintenance report by nowlan and heap of united airlines that was sponsored by the us department of defense. Regardless of your knowledge or skill level you will learn things to take away from this training course. By extending the pf interval, conditionbased maintenance cbm. In this article, we will discuss the pf interval, how it is applied and whether it can be applied to equipment fitted with realtime. Promis portal facilitates employees to login to a universally managed central web server and address their enquiries. In addition to software like a cmms, each organization should go.
The impact of maintenance on the service life of assets. Running machines in runtofailure rtf mode is an appropriate strategy for assets where the consequence. Oncondition maintenance using pf interval or failure. Provident fund employee online self service portal software pf portal software is an online software to address the employee enquiries on pf balance, loan eligibility, pf annual statements etc. The pf curve illustrates the relationship between the warning signs that are detectable by various technology or methods and the progression of the failure. Aug 15, 20 why people do not understand the pf curve 1. It describes a particular form of the hazard function which comprises three parts. This is extremely useful if not essential for good condition monitoring. The eventual failure of any equipment is inevitable. Potential failure p is the loss of some protective granules from the cap.
Planning and scheduling with the pf curve the basics of the pf curve. A common curve that illustrates the behavior of equipment as it approaches failure is the pf curve. Points have been placed along the curve to represent a period of time pf from defect detection point p to functional failure point f. Predictive maintenance pdm technologies along the pf curve in relation to potential failure p and functional failure f. An introduction to the fundamental concept of the pf curve where we can identify the point of functional failure what the user wants it to do and proactively find it in the act of failing prior to that point. Set on an xy axis where x measures time and y measures the condition of an asset, the curve aims to represent the behaviour of an asset before it actually fails.
Introduction to reliabilitycentered maintenance this is an excerpt of the first chapter of the book reliabilitycentred maintenance by john moubray. Iconics offers free remote expert assistance software solution during covid19 crisis. A pf curve is a graph that shows the health of equipment over time to identify the interval between potential failure and functional failure. The preventative maintenance pm task had to be performed before issues were to become failures. Euromaintenance is known as the summit for all involved in maintenance across europe, its the place to be. This article has been updated since its original publication to reflect a more recent version of the software interface. It illustrates an assets progression toward failure. Exakt summarizes the risk factors associated with working age and monitored variables and creates a new kind of graph by transforming the significant risk information onto a 2dimensional optimal decision graph. The pf curve revisited hp reliability, an eruditio llc. This was an improvement, but it was difficult to optimize the timing of the tasks. It is more important to structure the design so that future changes can be made more easily.
Maximizing the pf interval with predictive maintenance. Machine maintenance is an essential component to any industrial operation, but all too often, these processes are neglected if not ignored entirely. The pf interval is it relevant in the world of big data. A pf curve is a visual representation of an assets deterioration over time, explains david albrice, senior asset management consultant at ch2m. The pf interval is a key concept when selecting preventive maintenance tasks. The pf curve is the time between a change in some parameter away from the norm, indicating the point of commencement of decay. This short video introduces the concept of the pf interval one of the core principles that underpins reliability centred maintenance and preventive maintenance program development.
How a pf curve can improve preventive maintenance efforts. Maximizing the pf interval through conditionbased maintenance. The bathtub curve is widely used in reliability engineering. Over time, this has come to include multiple wordings that describe various costeffective practices to keep equipment operational. Connect with an advisor chat with a software advisor and get personalized software recommendations via phone or email. Dec 06, 2018 cmms software is essential here, as it allows you to look back at work order history, failure data, and your maintenance schedule. Join over 14,000 maintenance professionals who get monthly cmms tips, industry news, and updates.
The complexity and nature of interactions between component is the most important consideration here. Staving off failure with maintenance is often not as simple as doing the same inspection at a set interval. The software finds the t p which minimizes the long run per unit of working age maintenance cost c t t t. Intro to the maintenance pf curve tpickett 81815 11. Since the equipment defect or failure has already begun, this region is about detecting and predicting equipment failure modes. Intro to the maintenance pf curve amp maintenance forums. Major maintenance tasks plotted on an asset deterioration model. Free curve images software free download free curve images.
When combining all these aspects, the full ratio of the equipment is laid out so the user can see in what time span a machine is supposed to break down. Illustration of a deterioration model for a roof system. Reliability centered maintenance the field of reliability is well established with years of research and development originating in the. We can say that most failures take time, and for that we can be thankful. Jun 01, 2012 an introduction to the fundamental concept of the pf curve where we can identify the point of functional failure what the user wants it to do and proactively find it in the act of failing prior.
The reliability impact within the pf curve reliabilityweb. An introduction to the fundamental concept of the pf curve where we can identify the point of functional failure what the user wants it to do and proactively find it in the act of failing prior. The pf curve has become an essential component to any reliability centered maintenance program, and being able to understand it can help extend the lifespan of your machines by more than you might think. As with any maintenance process, it is greatly enhanced by knowledge of how assets operate normally and how they can fail. Maintenance is carried out when certain indicators give the signaling that the. Well help you narrow down software options in just a few minutes. This software, in my opinion, is the best value out there in the cmms world. Curve3 also has a new demo mode which allows users to test the interface as well as the main calibration and verification functionalities of curve3 including verify mode without a serial number. The conference, with the support of the efnms, is the only commercially independent conference covering the topics we deal with in the maintenance world. Preventive maintenance of fiber optic cables and optics the end of a fiber optic cable and the inner surface of an optical module lens constitute optical surfaces that should be properly c leaned and maintained to ensure optimum reliability and system performance. When talking about the pf curve, we must go back to the reliabilitycentered maintenance report 1 by nowlan and heap of united airlines that was sponsored by the u.
The bathtub curve, displayed in figure 1 above, does not depict the failure rate of a single item, but describes the relative failure rate of an entire population of products over time. The dipf interval and how to align your maintenance strategy the diagram below illustrates the dipf interval, created by doug plucknette, president of reliability solutions inc. Ges advanced gas path agp is a great example of power flexefficiency at work, setting new standards in performance. By extending the pf interval, conditionbased maintenance cbm methods provide the earliest possible prediction of equipment failure, with maximum benefit. The first part is a decreasing failure rate, known as early failures the second part is a constant failure rate, known as random failures the third part is an increasing failure rate, known as wearout failures. The pf curve chart leads the way to reliable machinery. This problem is made worse when an organization uses maintenance software or eam enterprise asset management software that kicks out all pms for the month on the 1st and you think you have 30 days to complete the pms. Reliability centered maintenance vs condition based. Improving maintenance by adopting a pf curve methodology. All cmms suppliers say that, but i found this one to be exactly that. The software profession has a problem, widely recognized but which nobody seems willing to do anything about. Understanding the importance of proper equipment installation there has been much discussion and often debate around the pf curve. The method assumes that failure is a fairly random and unpredictable event, caused by the culmination of many factors.
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