Your technicians tell you they need more people.
Production wants to know why maintenance cannot keep up.
Your planner says there are 600 work orders sitting in the backlog.
Before you take that number into a meeting and use it to make the case for additional labor, there is a question you need to answer. How much work do those 600 work orders actually represent?
A one-hour work order and a 200-hour work order cannot carry the same weight in your maintenance backlog. Yet that is exactly what happens when an organization measures backlog by counting work orders.
The number may be accurate. It just does not tell you whether your problem is labor capacity, planning readiness, materials, equipment access or work identification.
To make better management decisions, you need to measure backlog in estimated labor hours and crew weeks.
You are hearing three versions of the same problem
At many plants, the maintenance manager hears three different explanations for why the work is not getting done.
The technicians say: we do not have enough people.
The planner says: I cannot get enough work ready.
Production says: maintenance already has hundreds of work orders.
All three may be describing something real.
The purpose of the backlog is not to prove one of them right. It should help you work out which constraint is controlling the result.
That starts by understanding what is actually sitting in the CMMS.
What is maintenance backlog?
Backlog is the future maintenance work documented in the CMMS that has not yet been completed. It is corrective and project work: the things you have found and not yet fixed.
Preventive and predictive tasks do not belong in that number. PM and PdM are among the first activities you run to break the reactive cycle, not a queue you are working down. Say on the report which convention you used.
Some jobs have been scoped, estimated and prepared. The necessary materials and special tools are available, and the work is waiting for the asset or the labor resource.
Other work orders contain little more than a short description of a problem. Some are waiting on parts. Some require engineering input, a permit or production access. Others have remained open so long that nobody remembers whether the work is still required.
Counting those work orders tells you how many records exist. It does not tell you how much work the organization has, or how much of it can be executed.
Separate total backlog from ready-to-schedule backlog
Total backlog
Total backlog includes all the maintenance work documented in the CMMS that has not yet been completed.
It should answer one question: how much known work exists?
For that answer to be credible, the work must have reasonable labor estimates. If a large share has not been estimated, the organization knows only how many work orders have been entered.
There is a way through that without waiting for every job to be planned. Have the planner put a quick educated guess on the duration the moment a work order lands in the backlog, then replace it with a real estimate when the job is planned. If you need a number before that habit exists, take a broad sample of your completed work orders, work out the average hours, and multiply that by the count of unestimated work orders. It is an average, so it will be wrong on any single job. It is close enough to stop half your backlog reading as zero hours.
Ready-to-schedule backlog
Ready-to-schedule backlog is the portion that has been properly planned and is ready to move into the schedule.
It answers a different question: how much executable work is available to feed the schedule?
A plant may have thousands of backlog hours and very little work that could confidently be placed on next week's schedule. That points at planning readiness rather than labor capacity.
A job is ready to schedule when it has all seven of these:
- Clear scope
- Craft identified
- Estimated labor
- Available or confirmed materials
- Identified special tools
- Known permits and supporting information
- Nothing left to wait on except the asset or the crew
Craft belongs on that list for a reason that shows up again in step one. A job with no craft on it cannot be loaded against anybody's capacity.
Why a count of work orders gives you the wrong picture
A one-hour guard replacement and a 200-hour major repair each count as one work order, even though one represents 200 times the labor.
Unestimated work inflates the record count without revealing the workload underneath it.
You cannot use that count alone to decide whether the plant needs more technicians, better planning, improved materials coordination or more reliable production access.
Step one: calculate your weekly labor capacity
weekly labor capacity = (maintenance employees x scheduled hours per employee) + contractor hours
Twenty maintenance employees at 40 hours each gives you 800 hours a week.
That 800 is paid time, not time available for backlog work, and the difference is worth taking seriously in a calculation whose whole purpose is to stop a number from flattering you. Meetings and breaks reduce the hours available for work before anything else does. You might get seven hours out of an eight-hour shift. Vacation, training, absence and shift coverage come out of it after that. A plant that subtracts none of them will read its crew weeks low. Start with the gross figure if that is all you have, and know which way it is wrong.
Run this per craft wherever crafts are scheduled separately. Three thousand two hundred hours that are mostly electrical, against four electricians, is a different plant from the same hours spread evenly across the crew. A single plant-wide number hides exactly the constraint you are trying to find.
The capacity basis needs to stay consistent across reporting periods. The goal is a number you can explain, repeat and trust, not a precise one you cannot defend.
Step two: convert backlog hours into crew weeks
backlog crew weeks = estimated backlog labor hours / weekly labor capacity
Take a plant with 3,200 estimated backlog hours against that 800-hour weekly capacity, with breaks and other reductions ignored here to keep the arithmetic simple.
3,200 / 800 = 4.0 total crew weeks
Now take the ready-to-schedule portion of the same backlog. Say 800 hours of it is genuinely planned and ready.
800 / 800 = 1.0 ready crew weeks
That plant has four weeks of documented work and one week that could actually go on next week's schedule.
What the numbers should be
Now you have two figures, and the question the whole exercise was built to answer. What is a healthy number?
Target four to six crew weeks of total backlog, and two to four crew weeks of ready-to-schedule backlog.
Those ranges have held up across industries for a long time, and they are the ones I have used with clients for years. Below the range on total backlog and you are usually not finding the work. Above it and you are accumulating faster than you can execute, which means overtime, contractors or a genuine capacity case. The ready-to-schedule range is the one that keeps a scheduler honest: fewer than two crew weeks of planned work and the weekly schedule gets built out of whatever is at hand, which is how a plant stays reactive while its planner stays busy.
Read the two together. That is where the diagnosis lives.
Go back to the plant in the example. Four crew weeks of total backlog sits inside the healthy range, so the volume of work is not the story. One crew week of ready-to-schedule work sits well under the two-to-four target, and that is the finding. The plant has a normal amount of work and cannot get enough of it ready to schedule. Adding technicians there does not change the outcome. It moves labor to the same constraint faster.
That is a different meeting from the one those 600 work orders were heading into.
What your figures may be telling you
Read the table against those ranges: four to six crew weeks total, two to four ready to schedule.
Five things can be controlling your result: labor capacity, planning readiness, materials, equipment access or work identification. A sixth, the credibility of the number itself, has to be settled before the other five mean anything.
| What you found | What it signals | Your first move |
|---|---|---|
| Ready under 2 crew weeks, total in range or above | Planning readiness | Find out why work is not becoming schedule-ready before you open a headcount discussion |
| Total above 6 crew weeks, ready in range or above | Labor capacity | Review labor loading, schedule compliance, priority discipline, equipment release and break-in work |
| Total under 4 crew weeks and ready under 2 | Work identification | Confirm defects and inspection findings are being written up. A genuinely proactive plant can sit here, so check before you celebrate or panic |
| Total 4 to 6 crew weeks, ready 2 to 4 | Nothing. This is the target | Hold the basis and re-run next month. Backlog is a forecast, so the trend tells you more than the snapshot |
| Large unestimated share | Backlog credibility | Put a planner's educated guess on the unestimated work so the total means something, then scope the oldest and highest-priority jobs |
| Much of it held for materials | Materials | Review purchasing processes, reservations, bills of material, lead times, stock accuracy, kitting and staging |
| Ready work waiting on a window | Equipment access | Take the held work into the scheduling meeting and agree release windows you can both hold |
Do not confuse a backlog list with executable work
Before a job counts as ready, somebody has to be able to answer all of these:
- What work needs to be performed?
- Why is the work required?
- What labor and skills are needed?
- How long should the job take?
- Are the necessary materials available?
- Are special tools required?
- Does the job require a permit or supporting documentation?
- What equipment access is needed?
- Is the priority still valid?
Your planner may own the daily maintenance of the backlog. You own the role clarity, the technician access, the storeroom coordination, the production participation and the protected planning time that let the process work at all.
Review the aging and obsolete work
Age the backlog before you judge it. Under 30 days, 30 to 60, 60 to 90, and over 90. The shape of that spread tells you more than the total does.
One thing to settle before you start pruning. Work deliberately deferred to the next outage or turnaround is supposed to sit there, sometimes for a year, and it is not evidence of a neglected backlog. Keep it on its own line and take it out of the aging review. What is left is the work that has aged because nobody dealt with it.
For that work, once it has been sitting a year, the odds are you are never going to do it. Backlog should not have birthdays. Ask:
- Is the defect still present?
- Is the work still required?
- Has the asset been modified or removed?
- Was the repair completed under another work order?
- Is the priority still correct?
- Does the description contain enough information to plan the work?
- Is anyone genuinely intending to execute it?
What comes off the backlog does not have to disappear. Some of it may belong on your capital or improvement list instead.
A healthy backlog is a managed pipeline, not a parking lot.
Start with one honest calculation
You need four numbers to begin:
- Weekly maintenance labor capacity
- Total estimated backlog hours
- Ready-to-schedule backlog hours
- The number of work orders without credible estimates
Calculate total crew weeks and ready crew weeks, then investigate the gap between them.
The result may show that you need more labor. It may also show that the work is trapped in planning, materials, approvals or equipment access.
The goal is not a better number for the monthly report. The goal is to know what is preventing your maintenance organization from executing the work.
If the constraint is labor, make that case with credible data. If it is planning, materials or equipment access, adding people will not solve it.
Work it through on your own numbers
The Backlog Reality Check is a printable worksheet that takes you through the calculation on your own plant's figures, then helps you read the result. It includes a fully worked example so you can see what a finished sheet looks like before you start.
Get the Backlog Reality Check worksheet
Where we can help
A backlog measured properly tells you where the work is stuck. It does not unstick it. Most plants that run this calculation find the gap sitting in planning readiness, and getting work scoped, estimated and genuinely schedule-ready is the substance of our Maintenance Planning and Scheduling course. Where the hold is materials, the fix lives in the storeroom and we teach that separately.
Maintenance backlog FAQ
What is maintenance backlog?
Backlog is the future maintenance work documented in the CMMS that has not yet been completed. Counting those work orders tells you how many records exist, not how much work the organization actually has. Measured properly it is expressed in estimated labor hours, and then converted into crew weeks.
How do you calculate maintenance backlog in crew weeks?
Divide your estimated backlog labor hours by your weekly labor capacity. A plant with 3,200 estimated backlog hours against 800 hours of weekly capacity, with breaks and other reductions ignored to keep the arithmetic simple, has 4.0 total crew weeks. Run the same calculation on the ready-to-schedule portion to get ready crew weeks, then investigate the gap between the two.
How much maintenance backlog should you have?
Target four to six crew weeks of total backlog and two to four crew weeks of ready-to-schedule backlog. Read the two together. Total inside the range with ready below two crew weeks points at planning readiness rather than headcount. Total above six with ready in range points at capacity. Total below four with ready below two usually means the work is not being identified in the first place.
What is the difference between total backlog and ready-to-schedule backlog?
Total backlog is all the documented work that has not been completed, and it answers how much known work exists. Ready-to-schedule backlog is the portion that is scoped, estimated, material-ready and waiting on nothing but the asset or the crew. A large gap between the two points at planning readiness rather than labor capacity.
Jeff Shiver, CMRP, RCM2 & RCM3 Practitioner, is the Founder of People and Processes, Inc. with 35+ years on the plant floor.