Does a one truck shop need written procedures
Mostly no, and it is worth saying that plainly on a site that sells procedure software.
When it is not worth your time
If you are the only person doing the work, the procedure lives in your hands and writing it down changes nothing about how the job gets done. The consistency problem that procedures solve does not exist when there is one person.
Spend the time on pricing, on the estimate that goes out same day, and on the review after the job. Those move money now.
The first situation where it starts to matter
The week you decide to hire. Not the week the person starts. Everything you know is currently unwritten, and the fastest way to write it is to record yourself doing the work over the month before, which is only possible if you start before the pressure arrives.
Shops that hire first and document afterwards spend the first three months training by ride along, which costs two wages for one output.
The second situation
Anything you do that could hurt someone else or destroy property. Gas, electrical, working at height, water in a finished space. Not because a written procedure protects you legally on its own, but because writing it forces you to decide your own rule and then follow it, particularly at six in the evening when you are tired and tempted to skip the test.
What a solo version looks like
Five procedures, not fifty. The jobs where a mistake is expensive. Printed on a card in the van rather than in any software, because there is nobody to distribute them to and nothing to record.
Come back when there are two of you. That is the point where the record starts to be worth something, and not before.
Keep the record, not just the paperwork
Copy anything on this page into your own documents at no cost. What Intulix sells is the part underneath: a signed, dated, version locked record of which technician read which version, exportable as a PDF when someone asks. Start free or see pricing from $59 a month.