Most preventive maintenance checklists die the same death: someone downloads a generic template, prints it, tapes it to the machine, and within a month every box is ticked in the same pen stroke from three weeks ago. The fix isn't more discipline — it's a better checklist. Every line needs three attributes: the task, the interval, and the estimated minutes. With those three, the checklist prices itself (a rotary-screw compressor runs 43.75 tech-hours and about $3,700 a year at $85/hr), schedules itself, and survives audits. This guide covers what goes on the list, how to set intervals, and the math that turns a checklist into a budget.
A PM task has to be something a technician can verify in the field with a pass/fail result: inspect, measure, tighten, lubricate, drain, replace. "Check belt condition" fails because condition is an opinion. "Inspect belt for cracks, glazing, or >1/2 in. deflection; replace if found" passes, because two people looking at the same belt reach the same conclusion. Write tasks in that shape and pencil-whipping drops off on its own — the checkbox either got done or visibly didn't.
What doesn't belong: anything belonging to a work order instead (repairs, anomalies found during PM — those get written up and scheduled, not fixed mid-checklist), anything without an interval, and anything the OEM manual doesn't actually call for. A checklist that grows a line every year becomes a checklist nobody finishes, and an unfinished checklist provides no data.
Start from the OEM manual — not from a neighboring plant's schedule, and not from what the parts store recommends. The manual gives you two limits for most services, and the rule is simple: service at whichever comes due first.
| Asset | Anchor service | Typical OEM interval | What usually binds |
|---|---|---|---|
| Forklift (LP / IC) | Engine oil & filter | 250 run-hours | Hours — 6 hr/day hits it in ~6 weeks |
| Rotary-screw compressor | Oil change | 2,000-4,000 run-hours (fluid-dependent) | Hours at 8 hr/day ≈ annual |
| Diesel generator | Oil & filter | 200-250 run-hours or annually | Calendar — backup units log low hours |
| Rooftop HVAC | Filters | 30-90 days | Calendar |
| Fleet vehicle (synthetic) | Oil change | 5,000-7,500 mi | Miles |
| Fire extinguisher (NFPA 10) | Visual / maintenance / teardown / hydro | Monthly / annual / 6-yr / 12-yr | Calendar, always |
Two clocks run on every asset because oil, coolant, belts, and seals degrade with time as well as use. A generator that runs 100 hours a year still needs its annual service; a forklift running triple shifts hits hour limits long before any calendar date. Intervals are typical manufacturer-recommended planning ranges — your manual and duty cycle override everything in that table.
Once each task carries minutes, the year prices itself. Occurrences per year: daily tasks × operating days (a 5-day shop is 250, a 7-day plant is 365), weekly × 52, monthly × 12, quarterly × 4, semiannual × 2, annual × 1. Multiply, sum, divide by 60.
Run it for the compressor: 5 minutes of daily tasks × 250 days = 1,250 minutes; weekly belt checks 10 × 52 = 520; monthly leak and filter work 35 × 12 = 420; quarterly sampling and cleaning 60 × 4 = 240; the semiannual filter 30 × 2 = 60; the annual oil, motor, and separator service 135 × 1 = 135. Total 2,625 minutes = 43.75 hours, which is $3,718.75 of labor at $85/hr. At 8 hours a day over 250 days the machine logs 2,000 run-hours — exactly a conventional-fluid oil interval — so the annual service and the calendar converge on the same visit.
Now the comparison that sells the program to whoever signs the checks: unplanned manufacturing downtime is widely benchmarked at $260,000 an hour (an Aberdeen Group figure, circa 2016, cited across the industry since). The year of compressor PM costs 1.4% of one hour of downtime. You don't need a precise downtime cost for your plant to make that argument; you need the order of magnitude.
Pick the equipment type, set your operating days and labor rate, and get the full task list with annual hours, labor cost, and a printable sheet with a QR code.
Open the PM Checklist Builder →One checklist is a chore; a stack of them is a program. Roll the assets into a single schedule (our maintenance schedule template does the hours-versus-calendar binding for you across a fleet), level the load across the year so March doesn't carry 60% of the annual hours, and review intervals annually against what actually failed. If a component failed between services, the interval was wrong — shorten it or add the inspection. If a task has been checked 52 times with zero findings, candidates for lengthening are exactly that line.
The same hours math scales to whatever you maintain, from a single rooftop unit (8.5 hours, $722 a year) to a fleet of vehicles — if it's your car rather than a plant, our car maintenance cost calculator runs the consumer version of this same budget.
Preventive (scheduled before failure), corrective (fix after failure), predictive (condition-based, driven by sensors and oil analysis), and run-to-failure (deliberate, for cheap or redundant assets). Preventive checklists exist to push work out of the corrective bucket, where it costs multiples more and arrives unplanned.
Tasks a technician can verify in the field: inspect, measure, tighten, lubricate, replace. Each line needs three attributes — the task, the interval, and the estimated minutes. Anything subjective ("check condition") without a pass/fail criterion will get pencil-whipped within a month.
Service at whichever comes due first. A forklift running 6 hours a day hits its 250-hour service every six weeks; a backup generator with 100 hours a year still needs its annual oil change because oil, coolant, and seals degrade with time, not just use. OEM manuals list both limits for exactly this reason.
Depends on the asset's duty. A rotary-screw air compressor on a 250-day schedule runs about 43.75 technician-hours a year — roughly $3,700 at $85/hr. A rooftop HVAC unit runs about 8.5 hours and $722. Multiply per asset, and you have the labor budget the program actually needs.