FOR KARATE DOJOS
The person paying is not the person training
In most dojos a good part of the mat is under twelve, which means your customer is often a parent watching from the side of the hall with no idea what their child is working towards. Three months pass between gradings and nothing visible happens in them. That is where the subs get cancelled.
On your side of it: a register on a clipboard for forty children arriving in ten minutes, a subs tin, and a grading list written out by hand the week before every grading, from memory. That is how a child ends up put in for a grade they are not ready for, and fails in front of their parents.
KYU GRADES THROUGH DAN
Kyu grades, kihon counted in the hundreds
The karate template runs 10th kyu to shodan and nidan over kihon, kata and kumite, with each grade requiring the one below it. Kihon targets are set in the hundreds on purpose: a technique is graded on repetition, and a target a child reaches in a fortnight teaches them the wrong thing about karate. Kata is pass/fail with a scored run at grading speed, and principles like zanshin and maai are recorded as taught rather than measured. The kata order ships as Shotokan's; replace it with your association's.
What that changes for a dojo
A parent can see the ladder
What their child has passed and what the next belt asks for, between gradings, which is most of the answer to 'is this worth the subs'.
The grading list, not the grading panic
Who has met their grade's requirements and who has one kata outstanding, months ahead rather than on the Thursday.
Club nights that register themselves
A tablet in the foyer that children use faster than any adult, so attendance for a class of forty is recorded without anybody writing anything down.
Families, not individuals
Three siblings on one household's card is the normal case in a dojo, and the thing generic gym software handles worst.
SEE IT AS THEY WOULD
Step into a karate dojo
Four seats in a dojo that is mostly children, with a grading list and a squad class. It is Kaizen Karate Dojo, Albany, NY, an invented gym in a sandbox that resets every night, not a customer.

Sensei Hana Ishikawa
Owner — a dojo with a large children's programme
Runs Kaizen, grades four times a year, and has more under-twelves than adults. Start here: the kyu syllabus, the grading list, and the family memberships.

Sempai David Achebe
Senior instructor — 3rd dan, children's classes
Teaches the children's classes and half the gradings. Look at his roster and at how kihon repetitions are recorded against a syllabus that expects thousands of them.

Megan Lloyd
Front desk — check-in, subs, grading fees
Handles the desk on club nights and every grading fee. Look at how little of the dojo's business the desk can reach, and at the kiosk the parents use.

Ben Okafor
Member — 5th kyu, purple belt
Trains twice a week and is working on Heian godan. His progress page is what a parent looks at between gradings.