Maintenance is easy to see when it fails and easy to ignore when it works. A plant manager who has spent a year moving work from emergency repairs to planned servicing often has trouble showing leadership that it paid off. The usual report, a long table of work orders, hides the answer. A short page with three numbers shows it.
This article describes that page: which three numbers to use, how to collect them from records you probably already have, and how to read them honestly. For the case behind planned and predictive work, see how predictive maintenance reduces downtime. Here the subject is the report, not the sensors.
The three numbers
1. Unplanned downtime hours. The hours in the month when a machine or line was stopped without a plan. Take it from your stoppage log. Keep planned stops, such as scheduled servicing and changeovers, out of this number, otherwise good maintenance would make it look worse.
2. Repair cost. The total spent on repairs in the month: parts, external service, and the labour of your own technicians. If labour is hard to split, use hours multiplied by one agreed hourly rate. Put the cost of lost output in a separate line only if finance accepts how it is calculated.
3. Planned versus emergency work. Of all maintenance hours in the month, how many were planned in advance and how many were reactions to a failure. Show it as a percentage of planned work.
Why these three? The first shows what the business feels, the second what it pays, and the third whether the way of working is changing. If planned work grows while unplanned hours and repair cost fall, the savings are real. If only one of them moves, you have something to explain.
Where the data comes from
You do not need new software. Most plants already have:
- A stoppage log, even a spreadsheet, with machine, start, end and reason.
- Work orders or a maintenance log, with type (planned or corrective), hours and parts.
- Purchase or invoice records for external repairs and spare parts.
The weak point is usually the type of work order. If technicians do not mark a job as planned or corrective, the third number cannot be calculated. Fix this first: one required field, two values, and a short rule such as "corrective means we reacted to something that had already stopped or was about to". If the logs are scattered over several files, the approach in the manufacturing spreadsheet problem shows how to bring them together without a large project.
An illustrative example
The numbers below are invented to show how to read the page. They are not from a real plant.
| Month | Unplanned downtime (hours) | Repair cost | Planned work share |
|---|---|---|---|
| January | 46 | 21,000 | 48% |
| February | 41 | 19,500 | 51% |
| March | 44 | 22,000 | 55% |
| April | 33 | 17,000 | 60% |
| May | 29 | 16,500 | 63% |
| June | 31 | 15,000 | 66% |
Read the table from the right. The planned share rose from 48% to 66%. Unplanned downtime fell from 46 to 31 hours, and repair cost from 21,000 to 15,000. March is the instructive month: the planned share grew, but downtime and cost did not improve yet. A report that showed only March would have suggested that the change was not working. With six months in view, the direction is clear.
The page for leadership would then say, in three sentences: planned work is now two thirds of the total; unplanned downtime is down by about a third since January; repair cost is down by about 29%. Next step: extend the planned schedule to the two machines that still cause most of the emergency work.
How to read the numbers
Look at trends, not months. One bad month can be a single large failure. Show the last six to twelve months, or a three-month average, next to the current month.
Expect a delay. When you move from reacting to planning, repair cost can rise at first because you do servicing you did not do before. The savings show up later as fewer large failures. Tell leadership this in advance, so a temporary rise does not look like a failure.
Check the pair. Planned share rising with downtime not falling means the planned work is not aimed at the right machines. Downtime falling with a stable planned share may be luck, or a change in production volume. A short note on production volume prevents wrong conclusions.
Separate causes. If one machine causes half of the unplanned hours, say so. The report gets more useful when it points at where the next effort goes. If you want to find that machine with data, the starting steps are in condition-based maintenance: first data, a pilot line and the break-even point.
One page, one decision
Keep the report to one page: the table above, a small chart of each number if you like, and a short text. For each number write one sentence on what changed, and finish with one request or decision, for example a budget for spare parts on a critical machine, or agreement to schedule a downtime window for servicing.
Leadership reads many reports. A report that ends with a clear question gets an answer. A report that ends with a table gets a nod. If you build similar pages for other parts of the operation, the operations dashboard article gives ideas for keeping them short.
Mistakes to avoid
- Changing definitions quietly. If you move a type of stop from planned to unplanned, note the date, or the trend becomes meaningless.
- Reporting too many numbers. Ten numbers hide the story. Start with three and add a fourth only when someone asks a question the three cannot answer.
- Claiming savings you cannot show. Say "repair cost fell" when it did. Do not turn it into a saved amount unless finance agrees how it is calculated.
- Ignoring production volume. Fewer stops in a quiet month say little.
- Hiding bad months. An honest dip, explained, builds more trust than a clean line.
What to do this month
Pull the last six months of the stoppage log and work orders. Mark each job as planned or corrective, calculate the three numbers per month, and write one sentence for each. Show the page to one colleague from finance or operations and ask what question it leaves open. Then fix the definition that caused the most doubt, and use the same page next month.
Sources
- Your own stoppage logs, work orders and purchase records, collected as described; all figures in the example are invented for illustration.
- Our related articles linked above.