Auto repair capacity planning software: book by hours, not open slots

A shop with a full calendar and idle technicians is a common sight, and so is the reverse: a calendar that looks open while three cars are stuck waiting on the one tech who can do the work. Both come from the same gap. The appointment book counts slots. Capacity is about hours, and the two are not the same number.

Auto repair capacity planning software tries to close that gap. It compares the labor hours your technicians can realistically produce with the hours already promised, and tells you how much more you can sell before you start making customers wait.

The basic math

One dealer-service reference defines capacity this way: technicians multiplied by attended hours multiplied by productivity. Attended hours are contracted hours minus holiday, training and known absence. Productivity is the share of attended hours that actually gets recorded against a repair order. Managers and advisors are not counted, and an apprentice counts as the fraction of a technician they can produce.

Here is an illustration with made-up numbers, using that formula. Four technicians, eight attended hours a day and five days a week give 160 hours of theoretical capacity. At 85% productivity, the hours you can really sell come to 136. Leave out the productivity factor and you promise 24 hours you do not have. The formula comes from the VentaVid service capacity entry; the shop in the example is hypothetical.

Then subtract what is already on the board: carryover from yesterday, approved work waiting for a part, and a reserve for drop-ins and add-on findings. What is left is what you can sell today.

Three measures that get mixed up

Trade press uses three terms that sound alike. Ratchet+Wrench defines productivity as hours worked divided by hours available, and efficiency as flat-rate hours produced divided by actual hours worked. FenderBender adds a third, utilization, with a worked example: 32 hours working on vehicles out of 40 attended is 80% utilization, and 60 bid hours completed in that time is 187.5% efficiency and 150% productivity. That is a body shop example with different units, so do not carry its percentages to a general repair shop.

The point is to name which one you plan around. For a booking decision, the number that matters is how many sellable hours you have, which is attended hours times how much of them reach a repair order.

What the surveys say about the gap

The gap is not rare. In the 2021 Ratchet+Wrench survey, roughly two-thirds of respondents had technician productivity below 90%, and about 73% had efficiency below 100%. An older consultant article gives starting benchmarks of 90% productivity and 130% to 150% efficiency, and notes that at 90% productivity an 8-hour day means about 7.2 hours on cars. Treat those as old reference points for a conversation, not targets for your shop.

What capacity planning software does

A useful tool does a few concrete things:

1. Shows sellable hours by day. Not open appointment slots, hours, after absences and reserve.
2. Subtracts carryover and approved work. Work that was approved and is waiting on a part still takes a place in the line.
3. Warns before you overbook. If a new booking needs four hours of a specialist and the specialist has one hour left, it says so.
4. Watches the inputs. Effective labor rate is one of the numbers Tekmetric highlights, the actual dollars collected per labor hour after discounts, flat-rate work and packaged pricing. Together with car count and average repair order, it tells you whether the hours you fill are worth filling.
5. Reports honestly when data is missing. If a part ETA is unknown or a technician's schedule is not entered, a good tool says that instead of filling in a guess.

What stays with a person

• Deciding who can do what. Skills and certifications are judgment, not arithmetic.
• The reserve. How many hours to hold back for drop-ins depends on your customers and your season.
• Saying no or offering a later date. A person says it, in the customer's language.
• Choosing the target. Whether a given productivity level is realistic for your team is an owner's call.

A way to start this week

1. List your technicians and their real attended hours for next week, after training and time off.
2. Write down last month's productivity from your shop system, not a hoped-for figure.
3. Multiply, subtract carryover and a reserve, and compare the result with next week's booked hours.
4. Do that every Monday for a month. The first pass will be wrong, and that is useful information.

Where RevvOS fits

RevvOS does not run your appointment book or set technician schedules. It sits alongside the shop system and calendar you already use. Its daily operations view puts parts and capacity on the same short list as stale estimates and aging repair orders, so a delayed part and the schedule it affects are visible together. If a part has no delivery time, it says the time is unavailable instead of guessing. Each line shows its source and when it was last updated, and drafts wait for a person to review them.

Related reading: technician scheduling AI, auto repair operations software AI and auto repair shop automation. To scope one workflow, start with the Multi-Shop Operating Gap Assessment.