How do you know if you are actual making money from a solar project?

This may be considered a strange question!

You quote a job, you win it. Design the system, organise the personnel and materials, finish and get paid. So what was your gross profit, gross margin?

To answer these questions accurately you need to have impeccable documentation, checklists etc that capture the data on every aspect, from administration costs ( all those tedious hours of submitting paperwork to the distributors let alone the customer manual), what's happening on site ( how long did it take to tie in all that DC cabling into the cable tray on a 1 MW system) and of course commissioning. Sorry, I forgot the the cleanup!

So what approach do you take?

Do you use a spreadsheet? A dedicated program or software or whatever.

Interested to know.