PdM is Not Precision Maintenance (Coaches Corner)

Another great Coaches Corner post from Allen Canaday:
During a recent discussion with a student he asked me why the failure rate at their facility wasn’t improving.  Over the last two years they had invested in the purchase of various PdM (Predictive Maintenance) technologies and trained personnel on their use and application.  The facility had conducted a criticality analysis and SFMECA (Simplified Failure Mode Effects and Criticality Analysis) to determine their critical failure modes.  For the most part, they had purchased and trained on the PdM technologies that would best detect the early onset of the failure modes identified in their SFMECA.  Why were assets continuing to run to failure even though failure modes are being identified? Why aren’t the PdM technologies preventing failures in our facility, he asked?
The answer in two-fold. This wasn’t the first time I fielded this question.  When I asked the student about the precision maintenance techniques utilized in their facility, he asked, “What do you mean by precision techniques”?  This was exactly the answer I was expecting! PdM technologies are diagnostic tools designed to find the early onset of failure modes, these tools don’t make the repair for you, they just help you determine what needs to be repaired.  These tools can’t tell you exactly how long you have prior to functional or catastrophic failure, the data acquired from these tools only tell you your asset has a failure mode and if no action is taken, it will eventually fail.
Precision techniques and instruments, along with the proper training on their use, increases the probability that when the repair is made, failure modes aren’t introduced into the asset resulting from the corrective work.  Precision techniques include job plans that consists of proper task-step sequences and performance standards that convey proper tolerances and measures to the technician performing the corrective work.
Next, I asked the student to explain their backlog prioritization for planned work.  Again, he asked “What do you mean by backlog prioritization”? I explained that no matter what PdM technologies you utilize, the findings must be converted to a work order to be planned and scheduled.  Even the PdM generated work orders become part of the total backlog and must be scheduled based on their severity or risk to the organization.   Poor work order prioritization practices can render your PdM efforts meaningless unless your work execution practices are robust enough to effectively prioritize work orders in your backlog.
PdM is not precision maintenance!  The two complement each other.  However, without the implementation of precision maintenance in your work execution process, expect to continue making repetitive repairs on many of your assets, even on the assets you’re utilizing PdM technologies to detect the early on-set of failure modes.

Precision Maintenance: Belts, Chains, and Sprockets

Today's post by Brandon Weil will add the element of precision to your program.

Belts, chains, and sprockets, chances are you have at least one if not all of these in your facility, and chances are you’re relying heavily on experience and judgment instead of quantitative inspection criteria. All too often the importance of proper inspection techniques and defined replacement criteria for these critical parts are overlooked. Don’t believe me? Just pull up some of your PM inspection procedure, discuss the topic at a tool box meeting, or observe someone performing the inspection, you might be surprised at the range of answers and opinions. If there isn’t a specific measurement or min/max criteria then you’re leaving the inspection up to chance. Another thing to consider is if these parts aren’t being installed properly in the first place you will undoubtedly see premature failures and reduced operational life, inspection criteria applies to installation practice requirements as well.
The good news is that you can start improving the quality of these inspections; all you need are a few basic low-cost tools Click Here and you will find a document with inspection criteria for these three parts to get you started. Improving your PM inspection procedure, putting the right tools in the right hands, and setting quantitative standards for your inspection is a very low-cost high-return activity that can start paying dividends today.

Precision Maintenance: The Torque Wrench

The automotive industry has had a bout with torque related issues recently. This has included over and under torqued items that have lead to failures and even deaths. We see torque related issues constantly in manufacturing facility root cause analysis. Bearing with reduced clearances and life due to over tightening of the housings and loose components due to improper bolt type and complete disregard for torque specifications are just a couple of recent examples.  Part of the solution is proper use of a torque wrench. A torque wrench is a precision instrument designed to apply a specific amount of force to a fastener. Whether tightening head bolts on a small block V-8 engine, lugs for tire and wheel installation or inspecting fastener tolerances on high-performance equipment, it is extremely important that proper care is used.
Guidelines are typically provided noting acceptable torque ranges, the order in which specific fasteners are tightened and the number of times a fastener must be tightened and loosened to ensure uniform torque application. You must also be mindful of the presence of thread lubricants and the age of the bolt or fastener being used as these affect the torque required. Failure to properly torque fasteners can lead to equipment damage, personal injury or worse.To help you prevent torque problems in your facility I have collected a few tips for your use. There is also a video here for you visual learners.

It is important to follow acceptable safety, maintenance, and use practices, such as:
1. Always follow the manufacturer’s directions regarding torque direction, proper force, torque
pattern/sequence, use or non-use of lubrication on fasteners and torque “tighten/release” cycles.
2. Do not exceed the recommended working range of the torque wrench. Reliable measurements are
based on a percentage of the working range. In general, most mechanical wrenches have a useable
range from 20% to 100% of full scale. Most electronic wrenches have a useable range from 10% to
100% of full scale.
3. Do not use handle extensions or torque multipliers/cheater bars as we called them unless specifically allowed by the torque wrench
manufacturer.
4. If you have a torque wrench calibration/ verification stand test the wrench prior to each use.
5. Always inspect the tool and check for worn or cracked sockets. Properly lubricate and replace
worn parts.
6. Avoid dropping or sliding a torque wrench. Dropping a torque wrench on a hard surface can cause
the instrument to lose reliable calibration. If you suspect that a wrench has been dropped, have the
tool inspected by the manufacturer or reputable calibration service.
7. Always store a torque wrench in a protective case and/or location when not in use.
8. Avoid exposure to temperature extremes, high humidity, fluid immersion and corrosive environments. That means do not put them in the parts washer...
9. If using a click-type torque wrench, always store it at the lowest level on the scale.
10. Avoid marking, etching or placing labels on torque wrenches.
11. Use a torque wrench to apply a specific torque value during the final assembly process. Do not use a torque wrench as the primary means of tightening or loosening fasteners.
12. As most torque wrenches are length specific, always grasp the torque wrench in the center of the
handle. If two hands need to be used, place one hand on top of the other.
13. Apply torque in a slow, methodical manner and avoid sudden, “jerking” movements.
14. When the wrench signals (by clicking, beeping or lights) that a specific torque has been reached,
stop pulling immediately.
15. After 5000 cycles or up to one year of use, whichever comes first, have your torque wrench
inspected and re-calibrated by the manufacturer or reputable calibration service.

Precision maintenance is key to eliminating your infant mortality and reoccurring failures. A systematic torque application program can get you on your way.

Are You a Reliability Champion or Reliability Killer?

As I travel from plant to plant and facility to facility I see both Reliability Champions and Reliability Killers.
First, lets talk about the "bad guys." These are the people in the organization that are not necessarily against getting better but they do not "have the time" to make the improvements and certainly do not want to wait for others to either. These folks are quick to say "When is the asset going to be back up?" without asking "what caused the problem?" and "How do we prevent it from happening again?" These are the ones who will spend the companies money to buy predictive and precision maintenance tools but because of the learning curve, do not allow them to be used lest they slow down the repair process. Their goal is not to fix it right just to fix it again and preferably as fast as possible. During one extended visit to a site I watched the company spend a substantial amount of money on alignment equipment and training but as soon as the crafts tried to use them and took a few extra minutes the supervisor yelled at them "to get that stuff off there and use a strait edge. We have to get this line up!" He was a Reliability Killer.
So what does a Reliability Champion look like? They are still concerned with getting the equipment fixed but they allow that bit of extra time that can get us to root cause and improve the precision of the repair. They use your target business processes. They know if we take a little down time now then I prevent a lot of downtime in the future. Their definition of fixed is a permanent repair not one requiring baling wire, duct tape and a hammer. They like to fix it once and forget it (after it is recorded in the CMMS).
In the end the reliability killer can be neutralized and in some cases even converted to a champion. It starts with communication and the creation of awareness and then as the killer sees the error of his ways and why changing could benifit him then he can accept more knowledge that can used to correct the situation or at least stop the killing. It is not eazy but it is possible with a plan and the desire to communicate.
So which category do your leaders fit into? Are you the Champs or the Killers? What are your plans to change that?