Where does book time come from, and can you change it?

Book time arrives in your shop management system as a number with no history attached. A publisher researched it and a licensing deal put it on your screen. Where it came from stops being trivia the first time a customer asks why the job costs what it costs.

Key takeaways

• Customer-pay times come from independent publishers, and warranty times come from the manufacturer.
• Publishers run separate methodologies, which is why two guides disagree on one job.
• The number is an average, so half the jobs it covers run longer.
• A shop can adjust it, and the adjustment belongs in writing.

Who publishes the number

Two different numbers travel under the name labor time, and ALLDATA's own documentation separates them cleanly. Warranty time is "the estimated time a factory-trained technician needs to repair a component still under warranty, as determined by the vehicle manufacturer." Standard time, the flat rate an independent shop bills a retail customer, is "the estimated time a non-factory-trained technician needs to repair an out-of-warranty component, as determined by independent labor time publishers."

That distinction answers a question customers ask constantly. A dealer quoting warranty work is reading a manufacturer's number built around factory training and factory tools. You are reading a published number built around a technician who learned the vehicle on the job.

MOTOR has been in business more than a century and says its labor times are "researched using OEM procedures and validated by experts to reflect real-world technician experience and average repair durations." Mitchell 1 has published labor estimates for the aftermarket since 1946 on its own proprietary methodology.

Both of them tell you the same thing about the result. Mitchell 1 puts it plainly: the labor guides are still estimates that may contain individual errors.

Why your two guides disagree

A shop running two subscriptions finds gaps on the same job constantly, and there is nothing sinister behind it. Separate research teams, separate assumptions about tooling and access, separate refresh cycles. One guide updates a time after a model-year change and the other gets to it next quarter.

The labor guide comparison that matters for your shop is which one covers the vehicles you see most. A European specialist and a domestic truck shop will reach different conclusions from the same test, which is why our comparisons of ProDemand against ALLDATA and Identifix against ALLDATA focus on coverage rather than on which publisher is better in the abstract.

What costs shops money is leaving the disagreement unresolved. Two advisors pricing the same job from two guides produce two quotes, and the customer who calls back on a Tuesday gets a different number than the one they were given on Friday. Pick the primary. Write down when the second one wins.

The number is an average

A published time describes what the repair took across repeated attempts under working conditions. Half of the jobs behind that average ran longer than the number that got published.

So a technician who beats book time on a clean vehicle and loses on a rusted one is experiencing the guide working as designed. Technician efficiency measured across a month tells you something. Measured on one ticket it tells you about that vehicle.

The guides handle the variance by excluding it. Mitchell 1 states that its times leave out diagnosis unless indicated, hazmat disposal unless indicated, machine operations, removal of locking lug nuts, and the time needed to free parts frozen by rust or corrosion. Broken bolts and studs sit on the same list, as does cleaning contamination left behind by the component that failed.

Those exclusions are billable work that the published time never contained. A shop that treats book time as a ceiling gives that work away, every winter, on every suspension job that fights back.

Can you change it?

Yes, and shops do it two ways.

The first is a labor matrix, which applies a multiplier by vehicle age band. A 2003 truck takes longer than a 2023 one on the same operation, the guide publishes one time for the operation, and the matrix carries the difference. Shops in the salt belt run heavier multipliers than shops in Arizona for exactly the reason you would expect.

The second is a per-operation adjustment on jobs the shop knows the guide underestimates. Every experienced advisor has a short list of these. The list is worth writing down, because it is real knowledge about real vehicles and it currently lives in somebody's memory.

Two rules make either approach survivable:

1. Put it where every advisor can see it. An adjustment nobody can find gets re-derived from scratch by the next person, differently.
2. Record why. Six months later the reason matters more than the number, particularly when the vehicle changes and the reason stops applying.

Watch what the change does to your effective labor rate rather than to individual tickets. A matrix that looks aggressive on one quote often turns out to be recovering hours the shop was already losing.

What to say when a customer challenges the hours

The question comes in two forms and they need different answers.

When somebody says the shop down the road quoted less, the honest answer usually involves what each quote contains. A quote built from a published operation carries the whole job. A quote built by guessing carries whatever the person guessing remembered. Saying where your number comes from puts the conversation on ground you can defend, and most customers have never been told that a labor time is a published figure researched by a third party.

When somebody says there is no way the job takes four hours, the answer is that the four hours describes the repair rather than the person doing it. A technician who has done that job forty times will beat it. The customer is buying the repair.

Neither conversation goes well from memory. An advisor who can point at the operation and the publisher finishes it in a sentence.

How to test a guide against your own work

Shops argue about which guide is right without ever checking. The test is cheap.

Pick twenty jobs you run often, and for each one record the published time and what the technician's clock showed. Three months of that tells you where your guide runs light for the vehicles rolling through your bays, which is a different answer for a diesel shop than for a Honda specialist.

Two things usually fall out of it. Certain operations come up short every time, and those are your matrix candidates. Certain vehicles come up short across all operations, and that is an age band rather than a job.

The shops that do this stop having the argument. They have a list instead, and the list survives the advisor who built it.

What this looks like on the estimate

The customer sees hours and a rate. Everything above sits behind that one line, which is why the number feels arbitrary from the other side of the counter.

Shops that price straight from a published operation, apply a matrix they wrote down, and add the excluded work when it happens end up quoting the same job the same way in March and in October. That consistency is worth more than any individual adjustment. A customer who was quoted four hours in the spring and six in the fall for the same repair on the same vehicle remembers it, and no explanation lands well after the fact.

Mechanica prices from the inspection your technician already completed, with the published time and your own matrix behind every line, and an advisor reading the result before it goes anywhere.

Where book time stops answering the question

Two places, and both come up weekly.

The first is the job the guide does not carry. Restoration work, a heavily modified vehicle, something too new for the publisher to have caught up. There is no number to look up, and the shop builds one from its own recorded time on similar work.

The second is two operations sharing a teardown, where each published time contains the same access and stacking them bills it twice. That one has a published answer in the guides, and it is covered in labor overlap and what to bill when two jobs share a teardown.

Underneath both sits the distinction between the published time and the hours the technician was on the vehicle, which we cover in book time against actual time. A shop billing flat rate sells the published number. A shop billing actual time sells the clock. Most shops do some of each and the trouble starts when nobody has said which jobs belong in which bucket.

More on how the pricing comes together is on the blog.