Maintenance and Reliability Metrics

Actual cost to planning estimate: the report card on your planning's accuracy

The planner walks the job, counts the pipe sections, checks the rental catalogue, and logs a cost estimate of $3,170. The work order is approved, the job gets done, and when the final invoice lands it comes to $3,690.

Actual hours to planning estimate: whether your schedule is built on solid ground

The planner estimates twenty-eight labour hours for a carbon-steel pipe replacement: sixteen for the welder, twelve for the mechanic. The supervisor builds the week around that number, slots the job in, and lines up the trades.

Asset value per maintenance worker: how much plant each technician keeps alive

Two plants in the same industry, making more or less the same thing. One runs lean: every tradesperson has a full day's work, and the planning board is run like a railway timetable. The other carries a crew that simply feels right, the headcount i...

Availability, demystified

Availability sounds like the simplest word in the plant: was the asset available or not? Then you go looking for a definition and find half a dozen, each with its own formula, and the simple word suddenly feels slippery. The good news is that the ...

Availability: when you needed the asset, was it actually there?

The shift handover report says the line went down twice this week. One was a planned service that took an hour. The other was a coupling that let go without warning and pulled the machine out for most of a morning. Standing at the door, both look ...

Condition-based maintenance cost: what it costs to listen to your equipment

A vibration analyst walks the floor with a data collector, touching sensor points on pumps and motors. An oil sampler draws fluid from gearboxes on a set route. A thermographer sweeps a camera across the switchgear. Not one of them repairs a thing...

Condition-based maintenance hours: the team's time spent catching failures early

Two technicians spend Tuesday morning running thermal imaging routes across the switchgear and motor control centres. Another takes vibration readings on the critical pumps while a fourth draws oil samples from the big gearboxes. Not one of them t...

Continuous improvement hours: time spent making things better, not just keeping them running

A reliability engineer spends three hours a week reviewing failure data and looking for patterns. A supervisor joins a two-hour fishbone session after a safety incident. A planner gives a morning to a lean project on planning accuracy. None of tho...

Contractor cost: how much of the budget walks out the door to outside firms

The budget review arrives and the maintenance manager is asked why the cost line is so high. There are several possible answers, but nobody can say at a glance how much was internal labour, how much was materials, and how much went straight out th...

Contractor hours: how much of the work your own team actually delivered

A maintenance manager reviews the monthly report and sees that contractor spend is up. She also knows a turnaround ran that month and three specialist contractors were on site for two weeks. But she cannot tell whether the increase reflects that s...

Corrective maintenance cost: the share of your budget spent reacting instead of preventing

A maintenance manager pulls the monthly report: labour, parts, contractors, the lot. What she cannot see at a glance is how much of it was planned, proactive work, and how much was the crew scrambling to drag broken equipment back to life. The tot...

Corrective maintenance hours: the share of your team's time spent firefighting

The crew finishes Friday tired. Ask the supervisor how the week went and the answer is "flat out". Ask what share of all that effort was planned work versus fire-fighting, and he pauses. He knows it leaned reactive, he just cannot put a number on ...

Craft worker on shift ratio: a quiet gauge of how reliable your plant really is

Some maintenance workers follow the day shift and fill a structured schedule of planned work. Others are permanently rostered onto rotating shifts, their whole role built around being there when something breaks in the night or over a weekend.

Craft worker to planner ratio: is your planning function resourced or just overwhelmed?

The job gets called, the crew shows up, and then the waiting starts. The parts are not kitted. The permit is not ready. Nobody confirmed the scaffold. An hour of productive time evaporates before a single spanner turns.

Craft worker to supervisor ratio: can your supervisors actually lead, or are they just outnumbered?

One supervisor, thirty-two craft workers. On paper the department is fully staffed. In practice, that supervisor spends the whole shift firefighting, never finds a minute to check quality, and has nothing left over for coaching or a safety walk.

Direct to indirect maintenance personnel ratio: craft-heavy or top-heavy?

Every maintenance function needs two kinds of people: those doing the work and those enabling it. Too few enablers, and the craftspeople burn their day hunting parts, waiting on permits, and working from memory instead of a plan. Too many, and ove...

Idle time: the capacity you have already paid for but are not using

The compressor is in perfect working order. It passed its last inspection, the technician gave it a clean bill of health, and it could start this instant. Yet it has been sitting silent since Tuesday, because the process it feeds was shut down for...

Inactive stock: the dead weight on your storeroom shelves

Deep in the storeroom, behind the fast-moving shelves, sit rows of parts that have not moved since anyone can remember. Some were ordered for a machine that was replaced years ago. Others were bought in bulk and never fully used. They take up spac...

Indirect maintenance personnel cost: what you spend on support versus hands-on work

A plant manager works down the maintenance budget line by line. The labour figure is large, but how much of it is craft workers turning spanners, and how much is supervisors, planners, analysts and clerks? The two groups behave quite differently, ...

Internal maintenance employee cost: how much of the budget is your own people

A contractor-heavy maintenance strategy can look cost-effective on the surface, until someone adds up all the internal salaries, benefits and overheads running alongside it. A heavily insourced operation can look expensive, until you work out what...

Leading and lagging indicators: the scoreboard versus the steering wheel

The scoreboard at the end of a match tells you who won. It is honest, final and completely unchangeable. The steering wheel, by contrast, is what the driver uses during the race to influence where things end up. A plant needs both kinds of informa...

Maintenance cost per unit produced: the number that ends the budget argument

The spreadsheet is already up on the screen when you walk in, and Finance has colour-coded it. One cell is red, and it is yours: maintenance spend, up again on last year. The director taps it once and lets the silence do the talking.

Maintenance material cost: the balance between spending on parts and spending on people

A maintenance manager reviews the annual budget. Labour, contractors, service contracts and materials are all in the mix. She knows roughly what she spent, but not whether the balance between those categories is healthy or a quiet warning.

Maintenance shutdown cost: the turnaround bill, turned into a number you can budget

Once a year the plant goes quiet. The operators stand down, the contractors stream through the gate, and for two weeks the maintenance team works through a list that has been building since the last outage: vessels opened and entered, heat exchang...

Maintenance training cost: the easiest budget line to cut, and the most expensive

Budget season arrives and the training line gets squeezed. It always feels like the safe cut. The equipment is still running, nothing has broken yet, and the number sits quietly in a spreadsheet with no obvious consequence attached to shrinking it.

Maintenance training hours: turning good intentions into a number

Ask a maintenance manager how much training the team gets and the answer comes back confident: "We send people on courses." Ask how many hours per person last year, and the room goes quiet.

Maintenance training return on investment: making the case that training pays

The training budget is proposed and the first question from leadership is always the same: "What do we get for it?" Without an answer, the line gets cut. Everyone nods that training matters, and then the number shrinks anyway, because goodwill los...

Mean downtime (MDT): how long production really loses, not just how long the repair takes

Two plants run identical compressors, and both report the same average repair time: four hours. Yet one loses eight hours of production every time one goes down, and the other loses five. The repair is the same. The difference is everything that h...

Mean time between failures (MTBF): turning 'it keeps breaking' into a number you can improve

Two identical pumps sit side by side, doing the same job on the same line. One quietly runs for months. The other always seems to be on the repair bench, and nobody can say exactly how often, only that the crew sighs whenever its name comes up.

Mean time between maintenance (MTBM): how often you have to touch the machine at all

A reliability engineer is reviewing a critical conveyor. Its mean time between failures looks healthy, so on paper it is running well. Then she tallies up every maintenance action that actually stopped the conveyor last year, not just the breakdow...

Mean time to failure (MTTF): the lifespan of the parts you replace instead of repair

The instrumentation technician is replacing a batch of identical proximity sensors across the plant, and this time he logs each one: the day it went in, the day it stopped working. A year later he has ten little lifespans written down. Some sensor...

Mean time to repair (MTTR): how fast your plant gets back on its feet

A centrifugal pump trips at six in the morning. By the time someone notices it is down, calls out a technician, diagnoses the fault, hunts down the right seal, finishes the repair and hands the pump back to operations, it is nearly midday. Six hou...

Overall equipment effectiveness: the three honest questions

A line manager proudly reports that the machine ran all shift. True enough. But it spent an hour crawling at half speed, and a tenth of what it made had to be scrapped. Running is not the same as performing well, and to judge a machine honestly yo...

Overall equipment effectiveness: why a busy machine can still lose half its capacity

Walk the floor and Machine D looks like a hero. It is running, the operators are busy, the whole shift is a blur of motion. The board says the line was occupied all day, so surely it earned its keep.

Overtime maintenance cost: the most expensive way to get work done

A maintenance manager looks at the monthly payroll and notices the overtime line has been creeping up for three months straight. Each individual week seemed reasonable, a turnaround here, an urgent repair there. But stacked together they paint a p...

Overtime maintenance hours: keeping the volume picture honest

The overtime cost figure looks manageable, but is the hours picture telling the same story? Sometimes a modest cost premium hides a large volume of overtime hours worked by lower-paid grades, or a pile of extra hours concentrated on a single shift...

Planned backlog: do you have a healthy queue, or are you about to run dry?

The planner opens the system on a Monday morning and looks at the queue of fully planned jobs. Some are ready to go the moment a slot opens. Others are planned but still waiting on a shutdown window or a part on order.

Planned work: the clearest signal of how professionally your maintenance is run

The work order arrives at seven in the morning. The parts are on the shelf, the permit is drawn up, the task steps are written out, and the right tradesperson is already walking to the job. Twenty minutes later the pump is back on line.

Planner productivity: turning 'do we need another planner?' into a number

A plant has three planners on the books and a backlog that never seems to shrink. More work is called in each week than is prepared and scheduled, and nobody can say whether the planners are genuinely overloaded or whether their time is leaking aw...

Planning variance index: how often your estimates actually hit the mark

Reviewing last month's closed work orders, a maintenance manager notices that roughly one in four came in with costs more than ten per cent away from estimate. Some ran over, some came in well under, but either way the schedule built on those numb...

PM and PdM compliance: are your scheduled tasks actually getting done on time?

At the end of the month a few hundred preventive and predictive tasks were due, and the team closed most of them on time. The headline number looks perfectly reasonable, until someone scrolls back through the year and notices that a few months ago...

PM and PdM effectiveness: how much of the work you found actually needed doing

A time-based PM calls for a bearing to be replaced every six months. The mechanic strips the machine, inspects the bearing, and finds it in perfect condition. The replacement goes ahead anyway, because the work order said so. That job gets counted...

PM and PdM work order compliance: whether your worst delays hit your most critical assets

A monthly lubrication route is scheduled every 30 days. In practice it keeps getting bumped, and the crew settles into running it nearer every five weeks. Nobody sounds an alarm, because the work does get done, just a little late. Then a quarterly...

PM and PdM work orders overdue: a queue of deferred risk, sorted by what matters

End of the month, and the maintenance manager pulls the open work order list. Dozens of preventive and predictive tasks are sitting there past their due date. Some are a week late. Some are three months late. A handful are on assets that would sto...

PM and PdM yield: how much real work your inspections actually find

The maintenance team spends a great many hours each month on preventive and predictive rounds. The question nobody has put formally is the obvious one: how much does all that inspecting actually find? Is it catching real problems before they becom...

Preventive maintenance cost: the price of prevention, made visible

Every few months the lubrication routes run, the filters get swapped, the belts get checked, all on schedule. The work orders close without drama: no breakdown, no call-out, nothing to show for the effort except equipment that simply kept running....

Preventive maintenance hours: how much of your team's time goes to scheduled prevention

Every Monday a crew works through the weekly preventive routes: lubrication points, belt tensions, filter swaps, the round of visual checks. It is methodical, unglamorous work, and nobody ever won an award for it. Yet those hours are a deliberate ...

Proactive work: the clearest sign your prevention programme is real

Two plants run the same equipment. One runs its vibration routes, sticks to every preventive schedule, and acts on the defects those checks turn up. The other means to get to the preventive work, just as soon as things quieten down.

Proving the return on maintenance training

Every maintenance manager has heard the question, and dreaded it. You ask for budget to train the team, and management asks back: what is the return on this investment? Skill improvements feel real but are stubbornly hard to put in pounds or dolla...

Reactive work: how much of the week gets hijacked by emergencies

It is Tuesday morning and the planner has the whole week mapped out. Then the packaging line trips, and within the hour three technicians have been pulled off scheduled jobs to deal with it. By Friday the planned work is barely half done, and nobo...

Ready backlog: how many weeks of go-now work your crew has waiting

The scheduler sits down on Monday to build the week, and half the jobs on the list are not really buildable: parts still on order, a permit not yet drawn, a scope not yet worked out. The crew ends up filling the gaps with whatever is to hand, and ...

Replacement asset value: the number that sits under so many others

Ask two plants what they spend on maintenance and one says four million, the other forty. The big number looks alarming, until you learn the second plant is ten times the size. Raw spending tells you almost nothing on its own; you need something t...

Rework: the maintenance hours you spend undoing your own mistakes

A pump comes back from the repair bench and goes in on Monday. By Thursday it has failed again. The crew groan but say little beyond "it just wasn't right". A fresh work order is raised, parts are pulled, and four more hours disappear before anyon...

Schedule compliance (hours): did the crew's time go where the plan said?

The planner produces a tight schedule every Friday. On paper, 675 of the next week's 800 available crew hours are committed to specific jobs. By the following Friday, just 482 hours of that scheduled work are done. The rest was swallowed by emerge...

Schedule compliance (work orders): did the jobs you committed to actually get done?

The weekly schedule listed 135 work orders. By Friday, 113 of them were done on time. Another 45 emergency jobs had also been completed, but those were never on the schedule. They broke in.

Scheduled downtime: the planned price of healthy equipment

On Thursday afternoon the planner locks in next week's schedule. On it: a compressor service, a pump bearing replacement, a conveyor alignment. Each will take its machine offline for a measured block of time, and every one of those blocks is time ...

Standing work orders: the convenience that quietly blinds your data

Every Monday the lubrication technician charges four hours to a single work order that has been open since January. So do the housekeeping crew, the training hours, and the handful of minor adjustments that never felt worth a formal order of their...

Stocked spares value as a share of asset value: is your storeroom an asset or a liability?

Walk into a storeroom that nobody has questioned in a decade and you can read its history on the shelves. There are parts that have not moved since the plant opened. There are duplicates, bought because the first one could not be found. There is a...

Stock outs: how often a technician leaves the storeroom empty-handed

A technician arrives at the storeroom counter with a work order. The part is listed as stocked. But the bin is empty, and the job cannot proceed. The equipment waits, the crew waits, and a small gap in inventory has just quietly become a productio...

Storeroom records: does each clerk have a manageable catalogue to look after?

Two clerks look after a storeroom with 5,800 unique stock records. Each record stands for a part that needs a correct description, an accurate quantity, a sensible reorder point, and a designated bin. When records are poorly maintained, searches f...

Storeroom transactions: is your storeroom staffed for the workload it actually carries?

The storeroom has two clerks and a supervisor. On busy days the counter queue stretches back into the aisle, orders pile up in the receiving bay, and cycle-counting falls behind. On quiet days the team catches up. Nobody really knows whether two c...

Stores inventory turns: is your storeroom money working or just sitting?

A plant manager walks the storeroom and notices shelf after shelf of bearings, seals and filters that have clearly not moved in a long time. The bins are full, the dollar value on them is large, and yet the crew still occasionally runs short of th...

Systems covered by criticality analysis: are you maintaining what matters, or just what shouts loudest?

The planner is building next year's budget, and she needs to know where to aim it: which machines deserve the most spares, the closest watch, the tightest inspection routine. The asset register lists more than eighteen hundred systems, and not one...

The mean metrics: which one to reach for, and when

A pump keeps you up at night. Is the problem that it fails too often, or that it takes too long to fix when it does? Those are two completely different questions, and reaching for the wrong measure will send you chasing the wrong solution. The fam...

The types of maintenance work, and why the labels matter

Two plants both report ten thousand hours of maintenance last month. One spent most of those hours catching problems before they bit; the other spent them fighting fires. The headline number is identical, but the stories could not be more differen...

Total downtime: the honest sum of every hour you lost

At month end the operations manager pulls the production report, and the totals are lower than anyone expected. The equipment seemed to be available most of the time. Then someone actually adds up the hours the asset was stopped: the planned maint...

Total effective equipment performance: the score that counts every hour you own

Your OEE score looks respectable. The machine runs well when it runs, quality is solid, the speed is close to design, and the production team feels good about the asset. Then the finance director looks at the same machine and sees something comple...

Total maintenance cost as a share of asset value: the benchmark corporate asks for first

Two plants in the same business, much the same age, sit side by side in a spreadsheet. One spends what looks like a fortune on maintenance. The other spends noticeably less. On the raw figures the first plant is the spendthrift and the second is t...

Unplanned work: the honest measure of how reactive you still are

A bearing seizes at two in the afternoon. Nobody has the right part on site. A supervisor starts ringing round vendors, a planner is pulled off three jobs in progress to help expedite, and two mechanics stand idle while the right seal is hunted do...

Unscheduled downtime: the price of being caught by surprise

It is two in the morning on a Tuesday when the shift supervisor's phone rings: a gearbox has seized and the packaging line has stopped dead. There is no job order, no kitted parts, no team standing by. By the time someone is called in, the right s...

Uptime: the honest count of hours your asset was genuinely working

At the end of the month someone asks how the packaging line did. The operator says it ran well. The planner says a lot of time was lost. The maintenance coordinator says there was only one real breakdown. They are all describing the very same mont...

Utilisation time: how much of the clock you actually choose to use

A facility runs one eight-hour shift, five days a week. The equipment inside it is immaculate: it rarely breaks down, it makes good product, and whenever it runs, it runs well. On every maintenance measure, the team is doing its job.

Vendor managed inventory: handing the routine restocking to your suppliers

A storeroom clerk spends half her week reordering nuts, bolts, cable ties and lubricants. She counts them, raises purchase orders, chases deliveries and puts them away. Every hour on that is an hour not spent cycle-counting, rationalising duplicat...

Work order aging: the backlog you stop seeing

Pull up the active work order list and sort it by creation date. Somewhere near the bottom you will find orders raised six months ago, a year ago, some older still. Nobody cancelled them. Nobody finished them. They just aged, quietly, while newer ...

Work order cycle time: how long a job really takes, from request to closed

A work order is raised on a Monday in July for a minor gearbox inspection. It sits in the planner's queue, then waits for a part, then waits for a scheduled slot, and finally gets done in December.

Wrench time: how much of the paid day actually reaches the tools

Follow a skilled technician through a normal shift. She clocks in, waits for her assignment, walks to the storeroom, finds the part was never staged, walks back for a permit, waits for the equipment to be locked out, and finally picks up a tool we...