Guides
Tire shop KPIs: the monthly dashboard that matters
A monthly KPI dictionary for a tire shop: eight numbers with their formulas, data sources, edge-case rules, and what a bad reading usually means.
What to take away
- Define each number before you measure it. Two people counting a comeback differently produce a trend that means nothing.
- Eight numbers cover a tire shop. More than that and nobody looks at any of them.
- Count rework in bay minutes, not incidents, so a quality problem shows up as the capacity loss it actually is.
- The miss rate, jobs lost because the size was not on the rack, is the number this trade needs and almost nobody keeps.
- Read the numbers together. Any one of them alone can be improved in ways that damage the others.
The dictionary
| Number | Formula | Source | Read it as |
|---|---|---|---|
| Jobs per bay per day | Completed jobs divided by staffed bays divided by operating days | Job records | Output. Everything else explains it |
| Bay time by service | Actual minutes on the lift, median and slow end | Timed jobs | The input to prices and slot lengths |
| Comeback minutes | Rework minutes attributed to the original service | Job records plus rework flag | Capacity lost, not a customer service line |
| Miss rate | Jobs lost for want of the size, divided by jobs quoted | Miss log | How wrong your stocking list is |
| Contribution per bay hour | Price minus direct cost, divided by measured bay time | Invoices plus timing | Which services deserve the bay |
| Attach rate | Additional accepted items divided by visits | Invoices | Whether findings are being shown, not sold |
| Stock units by size and age | Count on hand, bucketed by age | Stock records | Cash tied up, and how stale it is |
| Booked share | Committed hours divided by available hours, a week out | Schedule | How much of the month is planned rather than hoped |
Settle the edge cases first
Every number above has a boundary somebody will interpret differently. Write your answers down once.
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.
What a bad reading usually means
Jobs per bay per day falling. Look at bay time first. Most drops are longer jobs rather than fewer customers, and the cause is usually a machine, a staffing change, or a new service that is slower than the menu assumed.
Comeback minutes rising. Check equipment before people. A balancer that has drifted produces vibration complaints across everyone who uses it, and drift does not announce itself. If it is concentrated in one person, it is a training conversation about a specific step.
Miss rate rising. 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.
Contribution per bay hour falling on one service. Either the job takes longer than it used to or the parts cost moved. Both are fixable once you know which.
Attach rate rising sharply. Good if findings are being shown with evidence, bad if it means people are being sold to. Check it against complaints and against your quality sampling before celebrating.
Stock age increasing. 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. Rising stock age ties directly to the tire shop pricing and profit decisions that set how much cash sits on the rack.
Booked share falling. Demand is softening, or your booking process is losing calls. Ask how many callers booked before assuming the first.
Read them in pairs
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
Put them side by side in the same monthly view so the tradeoff is visible rather than argued about.
The monthly routine
- Pull the eight numbers 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 all eight numbers at once cannot tell afterward which change did anything.
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
Where the data comes from
Most of it is in records you should be keeping regardless: job records, invoices, the schedule, the stock count, the miss log. The general expectation for business records, that they clearly show income and expenses and support what was bought and sold, is set out in the IRS guidance on what records a business should keep.
That data includes customer names, vehicles, and payment activity, so protecting it is part of running the shop.
The NIST small business quick-start guides cover the fundamentals plainly, and the CISA resources for small and medium businesses cover practical steps and current advisories. Individual accounts, multi-factor authentication, and a backup you have actually restored from cover most real risk.
Where these numbers connect
The system that stores and reports them, and the four data problems a tire shop system must solve, appear in the software and KPI guide.
Bay time and comeback minutes depend largely on the machines and layout in the equipment and setup guide. They also depend on the crew standard built through the hiring and training guide.
Whether demand exists to move jobs per bay is the trade-area question in the market and expansion guide.
Common questions
How many numbers should a small shop track?
Start with three: jobs per bay per day, comeback minutes and miss rate. Add the rest once those three are reliable and somebody is actually reading them each month.
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.
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.
What if the numbers contradict each other?
That usually means a real tradeoff rather than an error. Read the pairs above, and be explicit about which side you are choosing.
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.
