The bit everyone asks first
What happens to your existing data
It comes with you. All of it. Your rows get exported out of the spreadsheet, checked and imported into the new application, so on day one you open it and your jobs, customers, parts and history are already there. You are not starting from an empty screen and you are not retyping ten years of records.
Your original file is never touched. I work from a copy. The spreadsheet stays exactly where it is, on your drive, doing what it does now, right up until you decide to switch over. If you read the blueprint and decide not to bother, you have lost nothing.
And it goes back out again whenever you want. Every screen exports to a spreadsheet, so your accountant, your auditor or the person who simply prefers Excel can have the data in a file they can open without asking me for anything. That matters more than it sounds: it means your data never stops being yours in a format you control.
One caveat worth stating plainly: the data comes across as it is. If ten years of typing has left three spellings of the same customer name, those three spellings arrive with it. I'll tell you what I spot, but I can't warrant historic data I didn't enter.