Guides
Tire shop KPIs: where to look when a monthly number slips
When a tire shop KPI moves the wrong way, this shows how each number is counted, where to look first, and which pairs to read together before you act.
What to take away
- Check the definition before you blame the crew. A reading that moved because the counting moved is not a shop problem.
- When jobs per bay per day falls, look at bay time first.
- When comeback minutes rise, check equipment before people.
- Read the numbers in pairs, because any one of them can be improved in ways that damage the others.
- Pick one number to act on, change one thing and write down the date.
Check the definition before the shop
A reading that moved because the definition moved is not a problem with the shop. Before you chase any number, confirm that this month was counted the same way as last month. Every number has a boundary somebody will interpret differently.
Settle KPI edge cases
- Bay time starts at lift, not lot
- Torque recheckcomeback or not
- Declined then acceptedattach or new
- Special-order tiredelay, not miss
- Unstaffed bay excluded from jobs per bay
Consistency matters more than which answer you choose. A number defined differently in two months is not a trend, so settle each boundary once, write it beside the number, and change it only on purpose.
Where to look first
Each bad reading has a first place to look. Start there, because the obvious suspect is often the wrong one.
| The reading | How it is counted | Look first at | Then ask |
|---|---|---|---|
| Jobs per bay per day falling | Completed jobs divided by staffed bays divided by operating days | Bay time by service | Which machine, staffing change or new service got slower? |
| Comeback minutes rising | Rework minutes attributed to the original service | Equipment | Is it spread across the crew or one person? |
| Miss rate rising | Jobs lost for want of the size, divided by jobs quoted | The miss log, by size | Did the stocking list or a delivery pattern change? |
| Contribution per bay hour falling | Price minus direct cost, divided by measured bay time | One service | Did the job get longer or the parts cost move? |
| Attach rate rising sharply | Additional accepted items divided by visits | Complaints and quality sampling | Are findings shown with evidence? |
| Stock age increasing | Count on hand by size, bucketed by age | Cash on the rack | What is the shop holding that is not selling? |
| Booked share falling | Committed hours divided by available hours, a week out | Calls that did not book | Is demand softer, or is booking losing callers? |
Treat the table as a starting point, not a verdict. Two numbers can move together for different reasons, so read the record behind each reading before you act on it.
When output or capacity slips
Jobs per bay per day falls for a reason you can usually find in bay time. Most drops are longer jobs rather than fewer customers. The cause is usually a machine, a staffing change, or a new service that is slower than the menu assumed.
Comeback minutes rising points at equipment before people. A balancer that has drifted produces vibration complaints across everyone who uses it, and drift does not announce itself. If the minutes concentrate in one person, it is a training conversation about a specific step.
Booked share falling means demand is softening or your booking process is losing calls. Ask how many callers booked before assuming the first.
When stock and margin drift
Miss rate rising means your stocking list has fallen behind the vehicles on your road, or a supplier's delivery pattern changed. Read the miss log by size and the answer is usually obvious.
Stock age increasing means cash is being converted into rack occupancy. This does not appear in a profit figure, and it is how profitable shops run short of money. It ties directly to the pricing and profit decisions that set how much cash sits on the rack.
Contribution per bay hour falling on one service means the job takes longer than it used to or the parts cost moved. Both are fixable once you know which.
When a good number is suspect
Attach rate rising sharply is good if findings are being shown with evidence, and bad if it means people are being sold to. Check it against complaints and against your quality sampling before celebrating.
This is why the numbers belong together. Any single number can be improved in a way that hurts the shop.
Read KPIs in pairs
Pair
- Jobs per bay vs comeback minutes
- Speed bought with rework
- Attach rate vs complaints
- Selling vs showing
- Miss rate vs stock age
- Carrying everything buries cash
- Contribution vs booked share
- Niche vs strategy
Tradeoff
- Jobs per bay vs comeback minutes
- Attach rate vs complaints
- Miss rate vs stock age
- Contribution vs booked share
Keep each pair in the same monthly view, so that a gain in one number is never celebrated without a look at the number it can hurt.
The monthly review
- Pull every number on the same day each month, from the same sources.
- Compare against the previous three months, not against last month alone.
- Pick one number to act on. One.
- Write down what you changed and the date, so next month's reading has context.
- Review the definitions once a quarter to check nothing has quietly drifted.
The discipline is in step three. A shop that reacts to every number at once cannot tell afterward which change did anything. Keep the note short: the number, the change, the date and the reason. Three months later it is the only way to tell whether the change worked. The software and KPI guide covers where the data is stored.
Monthly KPI routine
- Pull eight numbers same day monthly
- Compare against previous three months
- Pick one number to act on
- Write down change and date
- Review definitions quarterly
Records behind every reading
A bad reading is only as good as the record under it. Most of the data sits in records you should be keeping regardless: job records, invoices, the schedule, the stock count and the miss log.
The IRS says good records will help you monitor the progress of your business, which is exactly what the monthly review does. It also lists supporting documents such as sales slips, paid bills, invoices and receipts, the documents that hold the figures you need to record in your books.
Common questions
Should the crew see these?
Yes, as process information. Comeback minutes by service invites the people doing the work to explain a trend, and they usually know why before you do. Presented as a scoreboard by person, it stops being useful and starts being avoided.
What if the numbers contradict each other?
That usually means a real tradeoff rather than an error. Read the pairs, and be explicit about which side you are choosing.
Is monthly often enough?
For most of these, yes. Booked share is worth a weekly glance because it is a leading indicator, and comeback minutes are worth logging as they happen rather than reconstructed at month end.
Do these replace looking at the accounts?
No. These explain the operation. The accounts tell you whether the operation is paying for itself, and the two answer different questions.
