[gesman]

I would start with customers and the end product.

Then think how would you build business from scratch to deliver products that customers need.

Then come back and make adjustments into the existing operation that fits your vision.

SAAS, hacks, shmacks may (or may not) be part of the process to optimize the business. Nothing wrong in paper, excels, quickbooks and order forms per se. If business is a smooth machine in operation - be careful in making drastic changes.