How do you scope a small, paid pilot for automating repetitive business work?

Hi all,

I've been working with small businesses where a lot of time goes into repetitive operations work. One example: a weekly sales report copied by hand from three spreadsheets every Monday, which takes about 4 hours a week.

My approach has been to treat each fix as a tiny project with a one-page brief that covers:

1. Problem and baseline: what takes the time today, and how much
2. Scope and deliverable: for example, an automated Google Sheets report plus a one-page summary, done in 2 weeks
3. Acceptance criteria: a measurable target, such as bringing 4 h/week down to about 45 min/week
4. Data rules: sanitized sample data only, and least-privilege access that is removed at the end
5. Commercials: a fixed fee agreed up front and released when the work is accepted

A few questions for the community:

1. What do you put in a lightweight charter or brief for projects this small, without drowning them in process?
2. How do you set acceptance criteria when the "customer" is a non-technical owner?
3. What risks have you seen when outside contributors get access to a small business's systems or data?

I'd appreciate hearing your experiences and any templates you've found useful.