On The Floor: Maintenance-Scheduling Triggers — Part 2 of 2

As noted in the April issue’s introduction to this, two-part “On The Floor,” when it rains, it pours. The overwhelming and detailed number of responses we received from our Reader Panelists regarding maintenance triggers simply wouldn’t fit in two pages. Alas, even with this second installment, we regret that we haven’t been able to capture all comments. To recap, we had asked these questions:

1. What triggers our Panelists’ maintenance scheduling, or if they are consultants or industry suppliers, that of their client(s) or customer(s)? Sensors? OEM recommendations? Daily walks/PdM tool data? Word of mouth? A combination?
2. Which approaches work best for them, and why, and vice versa?
3. Would Panelists (or their clients or customers) want to change their current maintenance-scheduling process(es), and could they? If so, what would they do?

Edited for brevity and clarity, here are several additional responses.

College Electrical Laboratory, Manager/Instructor, West…

In our organization, we have different levels of maintenance staff. The maintenance crew ranges from technicians who have been at the job for 22 years to the college grads with two to three years on the job. Their diagnostic methods are very different. The operation uses a CMMS program to track the health of all process equipment. The seasoned technician walks around and touches all of the equipment at least once a day, checking for temperature, vibrations, loose parts, and strange smells. The newer technician uses some state-of-the-art test equipment: infrared heat sensors, vibration monitor, and sound-level indicators. All data go into the system so any potential problems can be handled.

The process that works best varies because experience comes into play. Some pieces of equipment are very old and have their own personalities. Test equipment does not always catch some of the problems, but the experienced maintenance staff seems to be able to diagnose a pending problem through their touchy-feely methods. Keeping track of this history has reduced downtime on most of the equipment. Education on all processes and updated technologies has added to our success.

We’ve been able to add preventive-maintenance hours to the schedule when we have tooling changes and other production breaks. Each experienced technician has a newer technician assigned to him for in-depth training. Every shift has a 15-min. maintenance-planning discussion before starting the daily operations.

Sr. Maintenance Engineer, Process Industries, Midwest…

[At our plant] it’s a combination. Before last year, it was mostly set frequencies based on historical failure data, daily walks, or OEM requirements. Now, we have tied our real-time data-collection system to our EAM software and are doing more and more condition-based scheduling using online temps, vibes, run-hours, levels, etc. We still do “all of the above,” but have become more well-rounded.

I’m not sure there is a best approach. Any of them work. It’s dependent on the situation. In some cases, walk arounds are the best because the equipment is new, or not in a harsh service, or has no failure history. In other cases, we have to monitor key operating metrics very closely to detect slight changes that signal the start of the failure curve. The best approach is often learned from past results.

It would be great to have everything monitored online and condition-based, but it’s not feasible, so, we continue to be flexible and adjust where necessary, using all forms of monitoring to gather the needed data.

Planned Maintenance, Supervisor, Midwest…

Our maintenance is scheduled through a combination of methods. Sometimes maintenance, such as filter replacement, lubrication, and some oil changes, is performed after the equipment has operated a predetermined number of hours. Other areas we have been able to extend oil life through PdM methods such as oil sampling and analysis data. The majority of scheduled maintenance is the result of condition-based monitoring through our scheduled PM inspections. Sadly, the dreaded, unexpected equipment/component failure too often determines scheduling for us.

Lubrication best practices, combined with using the run-time hours of the equipment to determine lubrication frequency, have made a positive impact. Predictive oil sampling and analysis activities have given us a better understanding of the condition of our gearboxes and air compressors. Performing condition-based inspection tasks is key to allowing us to schedule maintenance in a timely manner that helps us avoid extended and untimely equipment outages. Of course, for all of the obvious reasons, the reactive, “repair after failure” type of work on production equipment should be avoided at all costs.

I hope to see more of our maintenance activities scheduled as a result of PdM activities. These include expanding and improving our oil-sampling program and developing and expanding the thermal-imaging best practices we are just getting started. I am convinced we would benefit from vibration monitoring and analysis and would like to see it added as one of the predictive techniques we use. I support these types of practices and the need to get key personnel formally trained to fully realize the benefits of these activities.

Sr. Facilities Engineer, Discrete Manufacturing, Southeast…

We basically begin with OEM recommendations and add to them as we learn more about the equipment.

I believe that, over time, knowledge is gained that must be implemented into the scheduling. Each user has different issues with the equipment and the OEM specs are just a jumping off point. How critical [certain] equipment is to your operation also comes into play.

Plant Engineer, Institutional Facilities, Midwest…

Our building engineers make daily rounds of all their buildings and track how long belts and air filters have been installed. Greasing equipment and any oil changes are done per OEM instructions, as best as we can. Our utility laborers change air filters, as needed, when asked by the engineer in each building.

We try to avoid breakdown maintenance as much as possible. Our chillers are rodded out at least once a year, and as needed. A contractor does winter maintenance on all stand-alone chillers, and we clean stand-alone cooling towers as needed after cleaning for season start-up.

We have several dual-temperature water buildings and normally only change each one from winter to summer and summer to winter annually. We try to do heating repairs in summer and cooling in winter. About 80% of our buildings use steam/chilled water from our utilities plants. Our plate and shell and tube heat/cool exchangers are cleaned/rodded as needed. We monitor our systems on CMMS as much as we can. About 60% is in the CMMS, but not all systems have full controls.

This approach works very well, considering how much equipment and how many employees we have. We take care of approximately half of a university campus, i.e., 7 to 8 million sq. ft., spread over about 40 buildings. We cover these buildings 24/7 with a combined crew of about 45 building engineers, laborers, and supervisors.

We’ve only had minor changes to our approach in the [many] years I’ve been here. The fact that all employees are taught it from day one seems to be the main [reason for its success].

And now, some final food for thought

Acknowledging that he has no current clients, a retired industry consultant still wanted to weigh in on the topic of maintenance triggers. His comments seemed to be a good way to bring closure to this two-part Reader Panelist discussion. Or maybe they’ll keep the discussion going in other places.

“I don’t have any current clients, (retirement tends to slow things a tad),” he wrote, “but those I had tended to perform as-per-schedule tasks, with reactive tasks done to fix the squeaky wheel.”

According to this respondent, only two of his major clients actually performed effective scheduled maintenance regularly. “The rest always seemed two steps from panic. Even with CMM programs and sensor-indicated needs, most were always attempting to catch up, typically complaining that a lack of staff or supplies was holding things up. Major contributors included poor problem-solving skills, fixing symptoms, not looking for root causes, or an attitude of ‘why mess with it while it’s working.’”

In his opinion, these problems are ongoing, in industry and elsewhere. “It seems that this is an international issue,” he lamented. “Worldwide, no one asks ‘why?’ Even here at home, life-style poor health is blamed on others (bad genes are becoming vogue, bad advice runs a close second), ignoring the basic fact that we are what we eat and modern North Americans have better choices than most medieval kings.” 

About the EP Reader Panel

The Efficient Plant Reader Panel includes approximately 100 working industrial-maintenance practitioners and consultants who have volunteered to answer monthly questions prepared by our editorial staff. Panelist identities are not revealed and their responses are not necessarily projectable. Note that our panel welcomes new members. To be considered, email your name and contact information to jalexander@efficientplantmag.com with “Reader Panel” in the subject line. All panelists are automatically included in an annual cash-prize drawing after one year of active participation.