Five Things You Need to Implement a Precision Maintenance Program
By John Lambert
Precision maintenance can be used as a process improvement strategy. A strategy that will pay dividends.
June 14, 2021
By John Lambert
This process is easy to implement. In fact, you do most of the work already. The beauty of it all is that there is not a lot of cost involved and if you’re smart, you can implement the process on one machine at a time.
In simplistic terms, precision maintenance means working to a recognized standard tolerance or specification. Just doing that will improve your work processes, and the payoff is a much improved and reliable machine (asset). It is important to note that “recognized” means that the standard is approved by an organization such as the Canadian Standards Association (CSA), the International Standards Association (ISO) or the American National Standards Institute (ANSI). There are many used in the industry, a common one is the ISO 10816 vibration standard tolerance chart.
Are there exceptions to using a recognized standard? Absolutely. There is the American Petroleum Institute API686, and while only a guideline and not a standard, this document was the go-to bible for anyone doing pump installations and still is.
When implementing precision maintenance, there are five things that you should already have or need to have to be successful.
1. Work procedures
Work procedures are written documents that follow the work process. You have them as part of your preventive maintenance program. But do you have them for a pump overhaul? The procedure should include the standard tolerances and specifications you would need doing the work. What this would give you is consistency. If you do not have written procedures or old outdated ones, the best people to write them are the tradesmen, as they know the work process the best. Better still, do it as a team building exercise as it creates buy-in. However, they must be clear, no ambiguity, all must understand and be on the same page.
2. Measuring tools
Precision maintenance requires exact measurement. Obviously, you need instruments that can achieve this. The actual recommendation is to use instruments that can measure under the tolerance you require. The tighter the tolerance, the better the result, but you cannot have a tolerance that you cannot measure. This means you need the right tools for the job. Always try to use digital so that the measured value or result is saved electronically. It is a known fact that when using instruments such as theodolites, dial gauges or levels for example, the greatest error occurs during the transfer of the seen value. One piece of advice is: do not buy junk. You need something that the team will use. Get them involved in choosing the tools required.
3. Data processing system
This is so important because it gives you an organized structure. You probably have a PM program, which of course is a must, that is controlled by a CMMS/EAM system. In it you will have planned work orders, back log orders, PM schedules, CBM tasks, etc.
Depending on the capabilities of your CMMS/EAM, you should have an individual file for all the plants assets. In each one, there should be a benchmark record of the machines normal operating condition. For example, the normal operation temperature and where you would take those measurements should be known to verify this. Simple enough to do, but so helpful for the PM tech. There should also be an asset history file.
And this is where we often see the breakdown in the system. There may be a file, but what is missing from many is the asset/machines installation report or a coming into service report. This is the information that controls the reliability of this machine. Imagine if you had to do a breakdown analysis after a failure and did not have this information? You would be relying on guess work or maybe wrong information.
A precision maintenance program guarantees that you have this file because a precision machine installation has mechanical measured items such as these below.
1. Base flatness and level
2. Shaft runout
3. Coupling runout
4. Pipe and conduit strain
5. Soft foot
6. Offline to running (OLTR) machinery movement
7. Shaft centerline to shaft centerline (alignment)
In today’s world of COVID, we use scientific knowledge to help us make choices about our health. That is not unlike what you do with your condition-based maintenance program.
All of these items and the recognized standard tolerances/specs can be found in ANSI/ASA S2.75-2017/Part 1. With an installation report and a commissioning report, it guarantees the machine has a good starting point when starting service. And throughout its life, there will be added work to this report such as an “as found” and an “as left” alignments, or a base flatness change as things do move over time.
1. The right skill sets for the work
A maintenance shop foreman once suggested that not everyone in the shop had the same sized toolbox and that he would pick and choose who to put on what job. What he meant was that not everyone has the same skill sets. For example, a company once bought an expensive and not so user-friendly laser alignment system. The problem is that not all the shop guys can use it. It may be taken to the job site, but unfortunately not used correctly or not used at all. This is one of the reasons we are developing training videos to help support some tradesmen who struggle with new technology. They can take their time and review it as often as they like, especially before going out to do an alignment job. With precision maintenance, all should be proficient in taking and recording measurements. So, you may want to invest in training.
2. The right team culture
I first heard the term precision maintenance from Ralph Buscarello of Update international, who taught me shaft alignment using dial indicators almost 40 years ago. Others were promoting this as the next big thing, but the reality is that it has been with us for a long time. Some companies, not a lot, do it, others do it but not as successfully.
If you are in maintenance, whether in management or skilled trades, embarking on such a program as this is challenging. It is a very worthwhile program, but it is a big commitment to do it and stay with it. The overall benefits are large in the form of machine/asset reliability. A side benefit is that you have to do this together as a group, dare to even say team, which does put some people off. However, there are different cultures that produce different teams. You may want to hug every morning before starting work but others will not. In today’s industrial environment, it should be evident to all that we have to work together in order to compete. So, the advice is that you sit down collectively and ask some tough questions, such as: can we do this and what do we need?
In today’s world of COVID, we use scientific knowledge to help us make choices or decisions about our health. That is not unlike what you do with your condition-based maintenance program, where decisions are based on the measurement/data that is taken. It is the same with this program. It is data driven. Quantifiable, reproducible measurements are taken, analyzed and compared to a standard. Decisions and/or actions are taken and the whole process is documented.
For well over 10 years, our training has been called MAAD, which is an acronym for measure, analyse, act and document. The suggestion would be that you do something along the same lines as this if you want to improve your maintenance process. And quite simply, do the job right, as you are doing the work already. MRO
John Lambert is the President of BENCHMARK PDM. He can be reached at john@ benchmarkpdm.com.