Technology Transfer Services Blog

There really is some truth to the old adage “If it ain’t broke, don’t fix it.”  Such a phrase seems naïve or misplaced in the context of preventive maintenance, but is it really?

 A great article by Drew Troyer of Noria Corporation discusses some of the issues that arise with preventive maintenance and how to avoid them.

  “Preventive maintenance is among the most common root causes leading to the need to perform corrective maintenance. It need not be. Evaluate your PMs and eliminate tasks that fail to add value or actually create failure. Eliminate the waste and ambiguity and properly assign the tasks at the proper interval, and avoid the temptation to knee-jerk react to failures by simply adding new PMs to the system or increasing the frequency with which tasks are executed without proper cause analysis. You’ll find yourself spending less money on preventive maintenance and, at the same time, increase the reliability of your manufacturing systems.”

 The steps to build a PM procedure have been described in many books, corporate policies, etc.  The process is typically data driven and mechanical to determine PM frequency.  However, the “art” is to consider the following three aspects of preventive maintenance:

1. Human Factors – Anyone who has performed routine maintenance on different models of cars can relate to this issue easily. On some cars, it may be simply a matter of lifting the hood or opening the glove box to access a fuse box. On other cars, accessing the fuse box might be equivalent to the twelve labors of Hercules. The harder it is to reach, the more likely something else will break accidently. The same issue applies to plant equipment.  Different motors, pumps, etc., may have the same basic PMs that need to be performed, but have varying degrees of access and ease of maintenance.  The “art” is to evaluate the likelihood of accidental damage to something else during the process of performing a PM based on physical location and workforce skill.
2. Domino Effect – As noted in the linked article, equipment failure probability generally increases immediately following preventive maintenance. So what happens after such a failure? Add another PM of course!  The best response to such a failure is to go back and evaluate why it happened and rethink the frequency of the original PM procedure. The right course of action might be to reduce the frequency of the PM, not to add another PM.
3. Collateral Damage – Wear and tear on components removed or accessed during preventive maintenance is a certainty.  An often overlooked aspect of PM program design is the interaction and impact of multiple PMs as it applies to wear and tear. Certainly maintenance planning involves scheduling of related PMs for labor efficiency and to minimize downtime of equipment. However, another factor to consider is the impact of the inevitable worn threads, sheared bolts, broken latches, etc.   The impact of such anticipated failures over time needs to factored into the frequency of PMs and should be planned for.

The bottom line is to temper the science of PM design with the art of considering the very real (yet hard to quantify) three aspects noted above.

Author: David Brent, Vice President

Most people take the safe operation of power plants for granted. Inside them are major components — including vessels, valves and piping — that operate under extreme pressure for years at a time. Yet the plant and others like it around the world run reliably and raise no alarm.

It’s probable that not one person knows just how many pressure vessels and miles of pipeline are currently in use. Every day they give us the electricity, fuel and steam that light and shape the modern world. But news photos from Manhattan in July 2007 show a gaping hole in Lexington Avenue which reminds us of what can happen when a steam pipe fails under pressure.

A steam pipe explosion beneath a street near Grand Central Terminal propelled a giant scalding jet of brownish steam toward the sky, sending commuters stampeding to safety. Officials said that one person died and more than 30 were hurt. Photo: New York Times

A steam pipe installed in 1924 ruptured in a thunderous explosion, sending steam, water and debris shooting outward through Midtown Manhattan. The authorities ruled out any criminal activity, saying the explosion was apparently caused by a failure of antiquated infrastructure. Photo: New York Times

The management of many power plants and their counterparts in the petroleum industry have methods for keeping operations safe and reliable. They know the risks posed by different parts of their work sites — the likelihood and consequences of failure of every major piece of equipment. They keep a close eye on the big-risk areas and react to early signs of impending failure.

The practice is called risk-based inspection. It lets companies weigh the risks posed by their equipment so they know how often they should inspect each key component and how to deal with the unexpected. It makes more effective use of resources and usually requires fewer shutdowns. Plants operate safely and companies save money.

The practice of risk-based inspection is less common outside petroleum and power generation businesses. That is the reason for a new American Society of Mechanical Engineers (ASME) standard, which is designed to introduce risk-based inspection practices and planning to a wider range of industries.

In the normal course of events, inspectors responsible for the safety and reliability of plants have a seemingly endless list of hazard areas to review, and all of these areas are given equal weight. Large parts of a plant or refinery are shut down so that the inspectors can do their jobs. Product flow and services diminish, and the company loses large amounts of capital.

The new ASME standard, PCC-3-2007 Inspection Planning Using Risk-Based Methods, was specifically developed for planning and executing risk-based inspection of fixed pressure-containing equipment and components. Equipment covered ranges from piping and boilers to pumps and compressors, from heat exchangers and furnaces to storage tanks and valves. Risk-based inspection planning takes the concepts of RBI and applies them to such issues as frequency of inspection.

Author: Phillip Smeall, Process Improvement Specialist

The dreaded maintenance department – a cost center most upper level management personnel would like to see disappear.  As a consultant in the manufacturing industry for the past 17 years, I am continually amazed at the lack of vision companies have when it comes to equipment maintenance and reliability.  Consider that when an assembly line goes down due to an equipment malfunction, it can cost upwards of $10,000 per minute in lost production. If your maintenance staff is not capable of fixing the problem in a timely manner, the downtime revenue losses can be staggering.
 
With the availability of such classes as auto shop, wood shop and metal shop diminishing from our nation’s schools, the concept of working with our hands has become foreign to a large percent of the population.  This is a big reason why the maintenance division has become the “mystery division.”  The notion that maintenance personnel carry around big hammers and crowbars still pervades the mindset of upper management, but the reality is that the maintenance staff has to understand complex processes controlled by high-end electronics.  If they are not fully trained, you can count on your unplanned downtime increasing.
 
Let’s compare your maintenance department to a hospital.  If you were in a car accident and got rushed to the emergency room, you would expect the doctor to be prepared to do whatever it takes to save your life. You would also expect that the doctor had been trained in all the techniques necessary to perform the job safely and effectively.  In a manufacturing facility, the maintenance personnel are the doctors. They have to be prepared to handle whatever emergency arises in a manner that is safe and efficient.
 
America’s skilled trades work force will be retiring in droves over the next five years. Are you prepared for such a dynamic shift?  Do you have a program in place to ensure your company’s “doctors” are going to be replaced by workers with the same qualifications?  If you’re not, the next time your line goes down and you see a maintenance person standing at the machine scratching his or her head, look at your watch and count the minutes.  Then ask yourself: how much did that just cost me?  

Author: Anthony Foskey, Chief Operating Officer