Your PPM schedule is out of date: how to review it

The gearbox on the infeed conveyor lets go on a Tuesday night. Your fitter pulls the PPM history to see when it was last looked at. Every month for three years, someone has signed off "Check gearbox". Not one entry has a reading, an oil level or a note.

Meanwhile the CMMS still sends out a weekly task for a shrink tunnel you scrapped last spring. Someone signs that off too.

That's what an out-of-date PPM schedule looks like. Nobody plans it that way. The schedule was written for the site as it was when someone last had time, and the site has moved on without it.

The problem is simple. A schedule that nobody reviews slowly fills with tasks that find nothing, and misses the failures that stop you.

Start with the breakdowns, not the tasks

Most reviews start by going through the PPM list line by line. We'd start at the other end.

Pull the last 12 months of breakdowns from your log, job sheets or CMMS. If your breakdown records are thin, our guide to a breakdown log that actually tells you something will help for next year. For now, use what you've got, even if it's the shift handover book.

For each breakdown, ask three questions:

1. Was there a PPM task on that part?
2. If there was, why didn't it catch the failure?
3. If there wasn't, should there be?

You'll find a pattern fast. Some machines break down again and again with a full PPM history behind them. That tells you the tasks are wrong, too far apart, or not being done properly. Others have no PPM at all and fail twice a year.

HSE's code of practice for PUWER backs this way of thinking. It says maintenance "should be targeted at the parts of work equipment where failure or deterioration could lead to health and safety risks" (L22, paragraph 73). Your breakdown list shows you which parts those are.

Find the tasks that never find anything

Now go the other way. Sort your PPM tasks by how often they've led to a repair or a part change.

Some tasks will have a long history of "checked, OK". That doesn't mean they're useless. A guard interlock test should pass every time. That's the point of it. But a monthly "inspect motor" with no reading and no finding in three years is a task that's using up fitter hours for nothing.

For each of those tasks, decide one of three things:

• keep it, because it's a safety check and passing is the right result
• change it, so it records a reading you can trend, like a temperature, a belt tension or an oil level
• stretch it or drop it, because the records show the part stays in good condition

Be careful with that last one. We'd only stretch an interval when you have proper readings to back it. Never stretch a safety check because the shift is busy. The code of practice warns that a fault in a safety-critical system "could remain undetected unless appropriate safety checks are included in maintenance activities" (L22, paragraph 71).

Check it still matches how you run

Sites change. A line that ran one shift now runs three. A product change means the filler does more changeovers. The warehouse added a mezzanine and the conveyors now run hotter and dustier.

The code of practice expects your schedule to move with that. It lists the things that should set how often you maintain: how hard the kit is worked, the operating environment, the variety of jobs it does, and the risk if it fails (L22, paragraph 72). It also says extra measures may need to be "reviewed and revised in the light of ongoing operating experiences" (L22, paragraph 76).

The electrical guidance says much the same. Under the Electricity at Work Regulations, HSE's memorandum says practical experience "may indicate an adjustment to the frequency" of preventive maintenance (HSR25, paragraph 68).

So go through your top machines with the people who run them. Ask how many hours, how many shifts, how many changeovers. If the answer has doubled since the schedule was written, the intervals are wrong.

While you're there, clear out the dead wood. Scrapped machines, moved machines, tasks for kit that's been replaced. Every ghost task on the list makes the real ones easier to ignore.

Rewrite the tasks so they mean something

"Check gearbox" tells a fitter nothing. Treat it as a hope with a tick box.

A good PPM task tells the fitter what to look at, what good looks like, and what to do if it's out. For that infeed gearbox it might read:

• check oil level at sight glass, top up with the grade on the plate if below the line
• feel and listen for heat and noise, compare with the gearbox on line 2
• check for oil on the floor and around the output seal
• record the casing temperature with the IR gun

That's four minutes of work, and every line gives you something to compare next month. If you want to go further on readings, our post on condition monitoring on a small budget covers what you can do with a few hand tools.

PUWER doesn't make you keep a maintenance log. L22 is clear that there's no requirement, though it recommends a record for high-risk kit (L22, paragraph 78). Where a machine already has a log, the law says it must be kept up to date (PUWER, regulation 5). Either way, a task with a reading is worth ten with a tick.

Count the hours, then be honest

Here's the part most reviews skip. Add up the hours the new schedule needs each week. Then compare it with the hours your team really has once breakdowns are taken out.

On a lot of sites, the two numbers don't match. The PPM gets planned for a full team and done by whoever's left after the night's breakdowns. Tasks slip, then pile up, then get signed off in a batch on a Friday.

You have three honest choices. Cut the schedule to what the team can do, starting with the least risky tasks. Move the big tasks into planned stops. Or bring in extra hands for the PPM backlog so your own fitters can stay on the breakdowns. What you can't do is leave a schedule on paper that nobody can deliver. Every skipped task on a critical machine is a breakdown you've booked in advance, and the cost of that stop will be far more than the hours you saved.

If you haven't ranked your machines yet, do that first. Criticality ranking shows you how, and it tells you where to spend the hours you have. For new kit, go back to the source with building a PPM schedule from the manufacturer's manual.

What to do on Monday

1. Pull the last 12 months of breakdowns and mark each one: PPM task or no PPM task.
2. Pick your five worst machines and rewrite their PPM tasks so each one records a reading.
3. Delete every task for kit you no longer have.
4. Add up the weekly PPM hours and compare them with the hours your team really has.

* Paragraph numbers refer to L22, fourth edition (2014, amended 2018), and HSR25, third edition (2015), correct as of 18 September 2026. Check HSE's L22 page and PUWER on legislation.gov.uk for the latest.