A Movement towards RCM

29th December 2017, Kolkata

On 29th December 1978, F. Stanley Nowlan, Howard F. Heap, in their seminal work Reliability Centered Maintenance, revealed the fallacy of the two basic principles adopted by traditional PM (Preventive Maintenance) programs – a concept that started from World War II:

  •  A strong correlation exists between equipment age and failure rate. Older the equipment higher must be the failure rate.
  •  Individual component and equipment probability of failure can be determined statistically, and therefore components can be replaced or refurbished prior to failure.

However, the first person to reveal the fallacy was Waddington who conducted his research during World War II on British fighter planes. He found that failure rate of fighter planes always increased immediately upon time-based preventive maintenance, which for the fighter planes was scheduled after every 60 hours of operation or flying time.

By the 1980s, alternatives to traditional Preventive Maintenance (PM) programs began to migrate to the maintenance arena. While computer power first supported interval-based maintenance by specifying failure probabilities, continued advances in the 1990s began to change maintenance practices yet again. The development of affordable microprocessors and increased computer literacy in the workforce made it possible to improve upon interval-based maintenance techniques by distinguishing other equipment failure characteristics like a pattern of randomness exhibited by most failures. These included the precursors of failure, quantified equipment condition, and improved repair scheduling.

The emergence of new maintenance techniques called Condition Monitoring (CdM) or Condition-based Maintenance (CBM) supported the findings of Waddington, Nowlan and Heap.

Subsequently, industry emphasis on CBM increased, and the reliance upon PM decreased. However, CBM should not replace all time-based maintenance. Time-based or interval based maintenance is still appropriate for those failure cases, exhibiting a distinct time-based pattern (generally dominated by wear phenomena) where an abrasive, erosive, or corrosive wear takes place; or when material properties change due to fatigue, embrittlement, or similar processes. In short, PM (Time based or interval based maintenance) is still applicable when a clear correlation between age and functional reliability exists.

While many industrial organizations were expanding PM efforts to nearly all other assets, the airline industry, led by the efforts of Nowlan and Heap, took a different approach and developed a maintenance process based on system functions, the consequence of failure, and failure modes. Their work led to the development of Reliability-Centered Maintenance, first published on 29th December 1978 and sponsored by the Office of the Assistant Secretary of Defense (Manpower, Reserve Affairs, and Logistics). Additional independent studies confirmed their findings.

In 1982 the United States Navy expanded the scope of RCM beyond aircraft and addressed more down-to-earth equipment. These studies noted a difference existed between the perceived and intrinsic design life for the majority of equipment and components. For example, the intrinsic design life of anti-friction bearings is taken to be five years or two years. But as perceived in industries life of anti-friction bearings usually exhibit randomness over a large range. In most cases, bearings exhibit a life which either greatly exceeded the perceived or stated design life or fall short of the stated design life. Clearly in such cases, doing time directed interval-based preventive maintenance is neither effective (initiating unnecessarily forced outage) nor cost-effective.

The process of determining the difference between perceived and intrinsic design life is known as Age Exploration (AE). AE was used by the U.S. Submarine Force in the early 1970s to extend the time between periodic overhauls and to replace time-based tasks with condition-based tasks. The initial program was limited to Fleet Ballistic Missile submarines. The use of AE was expanded continually until it included all submarines, aircraft carriers, other major combatants, and ships of the Military Sealift Command. The Navy stated the requirements of RCM and Condition-based Monitoring as part of the design specifications.

Continual development of relatively affordable test equipment and computerized maintenance management software (CMMS like MIMIC developed by WM Engineering of the University of Manchester) during the1990s till date has made it possible to:

  •  Determine the actual condition of equipment without relying on traditional techniques which base the probability of failure on age and appearance instead of the actual condition of an equipment or item.
  •  Track and analyze equipment history as a means of determining failure patterns and life-cycle cost.

    RCM has long been accepted by the aircraft industry, the spacecraft industry, the nuclear industry, and the Department of Defense (DoD), but is a relatively new way of approaching maintenance for the majority of facilities outside of these four areas. The benefits of an RCM approach far exceed those of any one type of maintenance program.

    Fortunately, RCM was applied in India for a few Indian manufacturing Industries from 1990 onwards with relatively great success. I am particularly happy to have been involved in development and application of RCM in Indian industries, which has continually evolved in terms of techniques and method of application to meet contextual industrial needs.

    I am also happy to report that RCM for industrial use has now reached a mature stage of its development, which can be replicated for any manufacturing industry.

    I am of the opinion that this maturity would provide the necessary stepping stone to develop Industry 4.0 and develop meaningful IOT applications for manufacturing industries.

    Wish RCM a very happy birthday!

    by

    Dibyendu De

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Self Organized Nemetic Environment for Learning (SONEL)

Have Fun & Learn
Mr. Shukla and I with the group of 28 who challenged Vibration Level 2 and Level 1 certification at PMI, Noida during last week of August 2012. 22 of these curious and brave souls successfully met the challenge.
Mr Shukla (from NTPC) is on my right and Mr. Anil Sahu is on my left. Both were my co-facilitators. As usual I am the shortest of the lot in dark green shirt.

Self Organized Nemetic Environment for Learning (SONEL) is a learning environment based on self inquiry of a person’s own problems helping one to instantly learn from those; supported by rich dialogs that build on each others ideas, questioning and peer learning aided by finding specific information from the internet.

Let me illustrate this through a practical example of how it is done.

The Story

NTPC (National Thermal Power Corporation) is the largest provider of power in India. They have a mission, which simply is to keep availability of their plants at the highest possible level. Since power plants like any other plant is a complex system it is not possible to plan out operation and maintenance activities in such a way to avoid sudden breakdowns and outages.

In order to do so they would have to base their actions on their understanding of the complexity or complex behavior of the plant and machinery. That is how we can work with any complex system, which creatively on their own keep changing their behavior. So the strategy is fairly simple — a) Understand the complex behavior of a complex system b) Spot an incipient failure growing or emerging c) Model that possible failure to determine what best can be done d) Take action to eliminate the failure or avoid it or reduce the risk of the failure to the minimum possible level e) Keep monitoring for the next emergence to appear.

In technical terms such a strategy is known as Condition Based Maintenance. That is the traditional name.  I don’t see any reason as to why it should not be called Complexity Based Management since the principles just remain the same. The same principles can be used over and over again to understand, decide and act in any complex environment, such as in organizations. I shall leave that discussion for some other day.

Coming back to our story one of the vital tools to implement such a strategy of knowing things in the now is Vibration Analysis, a very powerful tool since all machines and complex systems are dynamic and therefore vibrate in some way or the other. The tools and instruments of vibration analysis faithfully record the amount and the nature of vibration in various ways. However, only a human being can make sense of such records and form an understanding of what is going on. But the depth of understanding would vary from person to person depending on a person’s feel for complexity and understanding of the subject of vibration.

NTPC realized this very vital gap of enhancing human understanding in the whole strategy. This gap can only be filled through insightful and in-depth learning from a person’s intimate understanding of complexity informed by his/her practice. Hence they decided to expose as many people as possible to the subject of vibration analysis where they learn and apply their understanding to maintain a healthy level of plant availability.

So, every year NTPC organizes this all India SONEL event in Vibration Analysis Level 3 to Level 1 for their plants scattered all over the county. A suitability criteria is given, which basically sums up as ‘Are you practicing vibration analysis and complexity on the field?”. Against this criterion practitioners who are interested in challenging Level 3, 2 or 1 certification apply. Along with their applications they submit two case studies reflecting their failed struggle to understand the nature of complexity. The more intense their struggle as reflected in their cases better are their chances of being selected for the course. The idea is one can really learn very deeply from his/her cases and struggles. Only 25 students are admitted per batch.

Each candidate admitted to the course then submits at least two more case studies 15 days before the start of the course. From all the submitted cases (around 100 in number) the course work is carefully designed with a collation of appropriate questions to be used as triggers for live on-going classroom dialogs and peer learning.

Then a 4 day live workshop is conducted in the style of a concert. The only difference being that participants perform while I and my co-facilitators take up the role of the conductor. One by one participants lay bare their individual cases to the entire class with the hope of seeking a resolution of their problems.  They learn from the questions that are posed to them.  They learn from the ideas of others. They learn from the successes and mistakes of other practitioners who are their peers. Through the interactive sessions facilitators spot more weakness in the crowd and note them down for addressing them later. After some time through the rich dialogs the participants learn whatever they want to learn and decide on their actions customized to the problems they faced.  The atmosphere of serious play is constantly charged up further through more questions, interjections, explanations, suggestions and guidelines if any.

The questions for the final exam are formulated from whatever is happening live in the class and from the case studies.  The participants challenge the test by the end of the 4th day. Each participant is allowed to carry one A4 sheet of paper with their own notes, whatever they like to the examination hall. Obviously, I haven’t seen them using those notes since the final test is not a test of their memory, which I know they have in plenty. They get certificates as per the bands they achieve. For example, 90% and above get Level 3, 70 to 90% get Level 2 and 50 to 70% get Level 1. Below 50% get a certificate of participation.

Next year those in Level 2 come back to challenge Level 3 and those with Level 1 or with a participation certificate come back to challenge Level 2 or Level 3 along with a new batch of fresh candidates.  They can participate in the events twice a year. There is another interesting thing that happens on the side. A two hour video conferencing is conducted for all the plants for those participants who have already secured Level 3 certification.  It is a type of a feedback session trying to gauge as to how well the participants are doing. In most cases I found that their peers talk highly about them and their subsequent achievements in practice. That makes me proud indeed. Why not? Continued Peer Recognition is the best certificate in the world.

Notes:
  1. Self organized learning is learning on ‘my problems‘ through interactions with other human beings (including those on the net).
  2. The role of the facilitator is important. Conducting such a Self Organized Nemetic Environment for Learning (SONEL) is a tough job. One has to be on his/her toes through all sessions — in sharply creative and attentive mode.
  3. The quality of the interactions is important to achieve the learning goals. That is the job of the facilitators.
  4. Three facilitators work in tandem. One facilitator is drawn from the participating organization and one more knowledgeable facilitator is drawn at random from any other organization. In this case Mr. Shukla is from NTPC and Mr. A Sahu is from Birla Copper (shown in the opening photo)
  5. The learning follows the non-linear Nemetic process of a) Noticing/discerning changes b) Engaging with interdependent constraints c) Mull about the deep and rich interactions d) Exchange value through adaptation, re-design, actions etc. (NEME)
  6. This time around in Dec I shall tweak SONEL a bit more. The participants would set their own questions for an interim exam.
  7. This certification is now widely sought in India and employers are happy to see this certification for employment.
SONLE
Vibration Level 2 certification.