Maintenance backlog management is a field where a little creative paranoia is very helpful. The rest of the organization offers helpful advice in a variety of forms, and much of it can place maintenance planning firmly on the wrong track. Here are five of my favorite traps that well-meaning coworkers lay for the unsuspecting maintenance planner or manager.
Criticality by asset is a favorite of those who would oversimplify maintenance prioritization. The logic is that certain equipment is absolutely essential to production. Sometimes this determination is made by actual probability/risk number (PRN) computation, other times by review of process flow diagrams. The problem is that failure modes, not brass tag numbers, determine the criticality of a failure. If we list critical equipment and focus only on the most critical when assigning maintenance resources, we assign paint jobs and other non-essential tasks higher priority than more serious production, safety, or ecological problems with equipment that may not rate as high an overall criticality score.
Critical-asset logic will leave a maintenance planning function ignoring steam and air leaks, for instance, on non-critical assets, while pursuing cosmetic work on equipment judged to be critical. Well-meaning management and regulatory people make this kind of mistake routinely. Sometimes sanity can be regained by lumping non-essential tasks with turnarounds or plant-wide projects. Other times work just has to be scheduled out of priority order.
Production focus is another understandable but incomplete assessment tool that is often used to prioritize maintenance work. The logic here, again lifted from process flow diagrams, is that production equipment is the reason for a plant’s existence. Therefore overall equipment effectiveness (OEE) is the ultimate tool for judging the urgency of maintenance work. OEE impact is an important measure of maintenance effectiveness, but it is not the only one. It is not unusual to see a plant where maintenance tags, if they are used, or work orders are pulled for any equipment malfunction, but most safety and environmental issues are left unchallenged. Aside from the obvious danger associated with this approach, it sends a most unfortunate message to the workforce.
If you don’t have regularly scheduled safety and environmental tours of your operation, start. Take operators from each area and your best safety and environmental people with you. Also find a place for a safety code on each work order, and make sure safety and environmental issues get the priority they deserve.
Weekly global backlog review is a hallowed institution in many organizations. The review usually takes the form of well-meaning participants looking at a list of every open maintenance work order and deciding on a new priority order for all of them every week. It’s a lovely, social event, but it takes time and doesn’t move the work ahead. Instead, break up the backlog by area, trade, production system, or whatever zone structure makes sense in your operation, and conduct smaller meetings designed to get all the work in a zone done. Bundling work by area or trade reduces the non-wrench time spent by tradespeople, thereby making them much more effective. It can also combine permitting and other prep activities in a way that may double the amount of value-adding time delivered by maintenance staff.
Ignoring problem growth and recurrence is a trap that springs from human nature. A small drip that can be caught in a coffee can doesn’t look like a serious problem, especially if it’s an annual event. Unless trained to do so, many operators won’t even write work orders for mere drips. This doesn’t feel like a scheduling problem, but it is. Planners won’t even hear about small problems until they are big and the planning time is gone. Again, walking tours of plant areas, covering the whole operation on a regular schedule, are essential. This is part of establishing the kind of ownership and proactive problem reporting that keeps problems small. These surveys should probably be part of the safety and ecology training tours that you’re going to start. Oh, and a recurring problem isn’t something to ignore; it’s the sign of a design or process problem that needs to be fixed — now.
Lack of reliability engineering involvement happens a lot. If reliability people spend their weeks on failure modes that never happen while the maintenance organization deals with the same recurring problems year in and year out, then neither group is doing its job. The criticality measurements that most reliability techs and engineers use to drive their priorities include a multiplier for frequency of occurrence of each failure mode. This factor is usually ignored by reliability people, due to lack of information and, more to the point, lack of interest. Reliability priority drivers should include actual frequency data. They usually don’t. Actual failures are so much less tidy than conceptual failures.
Conversely, maintenance techs often don’t record adequate close-out data on work orders. Information on lessons learned and actual work performed must become part of the CMMS records. Solving problems once, permanently, is the responsibility of both maintenance and reliability.
Do you see some or all of these issues at work in your organization? Don’t just put a coffee can under it.