This article is an excerpt from the book “Maintenance Control” by Jim Borowski, a maintenance professional and UpKeep customer. Here he discusses how maintenance teams can improve their existing preventive maintenance and reliability program.
For most equipment, a scheduled maintenance program can be developed for improving or maintaining equipment reliability.
For the discussion in this article, the assumption is that a scheduled preventive maintenance program does exist in an organization. Proactive maintenance tasks of some sort have been assigned already. But, now we make another assumption, i.e., the PM program is not working very well. Equipment reliability is a concern. Some adjustments need to be made.
For our dysfunctional reliability program, there is no idea if the assigned proactive tasks are appropriate. This requires reason-checking. In addition, the frequency of the tasks needs looking at. Do the scheduled tasks make sense? Are they reasonable? Is there an objective measure recognizing the meaningfulness of the task?
If a PM program needs to have improvements made on the fly, where do you start? If you are the manager in this situation, what do you need to do? This we look at next.
Guidelines for improving an existing PM program
Revising and improving an existing preventive maintenance program for reliability takes time. It is not accomplished in a few weeks. Organizations have culture and ways of doing things. The revisions suggested here may go against current thinking. Patience must be the rule.
In lieu of a formal reliability centered maintenance (RCM), what follows are some suggestions or guidelines for improving an existing program of scheduled proactive maintenance tasks. The guidelines also come with a list of assumptions:
- An active maintenance management system exists.
- The organization uses work orders. Separate work orders are tied to each scheduled proactive task.
- Maintenance has the flexibility of assigning codes to the work order. These codes identify type of work and have the ability to link to other work. Examples of linking would be a follow-up work order tied to an inspection work order or child/follow-up work order tied to a parent for rebuilding a component taken out of service.
- The maintenance management system (CMMS) has a reporting function.
- By whatever means, proactive maintenance tasks have been assigned to equipment. Right or wrong, this will be starting point for improvement.
- The intent is to improve a possibly dysfunctional PM program — not make it perfect. At some later time, an RCM analysis could be made to corroborate the applicability of the current proactive maintenance tasks scheduled in the system — but not now.
10 Steps for improving your PM program
Step 1: Form a team of experts
Select a small group of experts to work on this project. It is helpful to include both maintenance and operations personnel. Consider a group of 3-4.
Step 2: Categorize equipment
Categorize equipment by Critical, Very Important, and Important. There most likely will be only a handful of equipment in the Critical category. This is where we begin — with the most important equipment in the organization.
Step 3: Select one critical asset
To start, just one piece of equipment is dealt with. Run a report in the maintenance management system to determine all the scheduled PM activities for this asset.
Step 4: Identify the failure mode
Identify the failure mode for the specific piece of equipment. Determine whether the equipment being analyzed has an age-related or non-age-related failure mode. The group needs to decide.
Step 5: Determine task types
One by one, review each task to ensure that it is a valid, meaningful PM task. Determine the task type. (i.e. inspection of equipment on-condition task, inspection for a hidden failure, restoration or overhaul task, or discard a task of a piece of equipment with a safe-life or economic–life limit.
Determine if the task aligns with the failure mode for the equipment type. If the equipment has a failure mode of non-age-related, then there should be no assignment of a restoration task for example. Or, if the equipment or component is capable of being rebuilt, there should be no assignment of a scheduled discard task. The group needs to decide.
Step 6: Review tasks in the CMMS
Review the specific task as it is represented in the maintenance management system (CMMS). Determine if the task is detailed enough and meaningful or if it has holes and can be improved. Make the appropriate adjustments in the maintenance management system.
Meaningful proactive tasks are very important. It does no good to provide services that equate to polishing chrome, adding nothing that extends equipment life. It does little good to provide only a partial service for a piece of equipment when much more is required. Look at the equipment with your own eyes. Is there something missing in the procedure or instructions that should be added or deleted to make the proactive task more meaningful? “Jiffy Lube” and “polishing chrome” PMs are not allowed.
Is the estimated or standard time appropriate? Should this be decreased for the sake of efficiency or increased for the sake of doing a better job and improved quality of work? The group decides.
Now, for that same piece of equipment, determine if any additional scheduled proactive tasks are needed – based on the group’s experience. Before leaving this equipment, all required proactive tasks needing to be assigned on a time-basis should be identified. After analyzing the tasks above, make necessary adjustments in the maintenance management system.
Step 7: Check the task frequency
Determine if the frequency is correct and make appropriate adjustments in the maintenance management system.
PM scheduling legacy
In many cases, the scheduling of proactive PM tasks has a legacy. For example, a piece of equipment sometime back may have experienced a random failure early in its projected useful life. Maintenance management at the time may have reacted by scheduling the PM task more frequently — maybe twice as often. This scenario is more common than might be expected. Look for any examples of this in your report. Purge the obvious PM’s that seem unreasonable.
In another instance, you may find that the frequency may seem reasonable, but there is no objective evidence that the task is doing anything to improve reliability. We will find below that there is a way that this can be identified.
PM scheduling and waste
Keep in mind that the intent is to stretch out PM intervals as long as possible, while still maintaining reliability. Performing the correct amount of service is the key. Providing too much service is wasteful.
For example, let’s assume that a scheduled proactive task costs $1,000. If the task is scheduled every 6 months, then the cost is $2,000 annually. A maintenance organization may arbitrarily feel that it can improve reliability by increasing the frequency of a PM. In this instance, a PM may be pulled ahead and performed every 4 months, which is a cost of $3,000 annually or a 50% increase.
In absolute terms, this may not be much. But, for significant numbers of equipment, pulling ahead a PM can be very costly. If 20 pieces of equipment are scheduled to have the same service performed and the PM is pulled ahead to 4 months from 6 months, the cost to the organization becomes an additional $20,000. If the scheduled frequency is appropriate, then pulling ahead a PM task is wasteful.
Equipment with an age-related failure mode
For scheduled restoration tasks, the correct frequency can be judged over time by inspecting the equipment coming out of service and making a judgment relative to remaining life. Technology and equipment design have improved over the years and remaining life for modern equipment may be quite different than for older equipment.
If the frequency specified for the equipment was established 10 years ago or more, it would certainly be worth looking at the remaining life of the removed equipment. This will take time, but should be done. Extending the restoration schedule can be a significant cost saving while not impacting reliability.
As we have seen, since age-related failure modes come with a potential of random failure, it may be wise to pair the time-based restoration task with a scheduled predictive on-condition task. You have to make the call based on experience and criticality. Changing out equipment based on condition is much more efficient and cost-effective than using time in service.
For restoration tasks that involve the exchange of components like motors, hydraulic cylinders, gearboxes, and the like, ensure that a follow-up work order is created to have the item rebuilt.
Equipment with a scheduled discard task
For tasks that are scheduled discard, the frequency is based on safe-life or economic–life limits. Not too much opportunity or decision making here. Stick with the schedule until conditions change.
Scheduled discard should not be applied to equipment or components that are rebuildable. If this situation does appear in your research, the task should be reassigned to a scheduled restoration task.
Equipment with failure-finding hidden tasks
For failure finding tasks, the correct schedule becomes a judgment call. Hidden failures are typically found in emergency and back-up systems that operate intermittently. When making a decision here, look at the amount of times that a hidden failure has been found. If over the period of a year not one hidden failure has been discovered and the task frequency is weekly, then it may be reasonable to expect that the schedule can be adjusted to a less frequent amount. This, of course, is based on the criticality of the system and what it is backing up or controlling.
If a hidden failure occurs and is not found and a serious safety issue arises, then adjusting the frequency may not be comfortable or reasonable for the organization. Again, this is a judgment call.
Equipment with scheduled inspections
This applies to equipment with either age-related or non-age-related failure modes.
For scheduled inspections of any kind, whether visual or predictive, the proper frequency is determined by an analysis of how many times something is found while performing the inspection.
If an inspection, whether visual or predictive, is conducted weekly and nothing is found for a year, then lengthening the frequency might be prudent. It would also reduce costs since PM inspections consume labor hours and take up budgetary dollars.
Tracking what is found on an inspection, whether visual or predictive, is performed with a follow-up work order. For example, if an infrared scan indicates that a crane control has a bad contactor, the act of changing the contact or is charged to a follow-up work order tied to the inspection. All costs and work history are tied to the follow-up work order, no costs flow to the inspection work order. However, with a link between follow-up work order and inspection work order, a report can be generated that shows how many follow-up work orders had been created for a certain inspection on various dates. This provides documentation for adjusting schedule inspection frequencies.
Scheduled inspections that consistently do not produce follow-up work are not worthwhile, adding nothing to a reliability effort. They need to be purged from the system.
To make any sense about the frequency of scheduled inspections, assigning and tracking follow-up work must be an option.
After analyzing the frequencies as indicated above, make the appropriate adjustments in the maintenance management system.
Step 8: Perform checks on remaining equipment
Continue the process until all selected desired equipment is assessed.
One by one, each remaining pieces of equipment should be analyzed in the same manner. It will get easier as time passes. Similarities will be seen and the same proactive tasks and adjustments made. After a time, the process will move more quickly.
Step 9: Set a goal
Set a goal for the team and report on progress. The PM optimization team should be assigned goals — so many PM’s evaluated per week. A report should be generated to monitor progress.
Step 10: Determine compliance for completion
Determine compliance for completing scheduled PM’s. A report indicating PM compliance needs to be part of the scheme. If a proactive PM task is worth doing, it is worth measuring to see that it is done on time.
Easily schedule and optimize PMs with UpKeep
Maintenance management software is a key component of the process for improving your PM and reliability program. If your existing software is too complex, UpKeep is an easy-to-use alternative that lets you update PM schedules and task frequency. You can also automatically create follow-up work orders for failed inspection items.
Jim Borowski has lived the life of a maintenance professional for decades by working as a frontline supervisor, plant engineer, and area manager; by implementing maintenance systems across multiple sites; by leading a corporate department responsible for maintenance best practices in a very large organization; and in the end by daring to act as a consultant.