The practical dividing line
If you can write the rule in one sentence, automate it. 'When an invoice passes 30 days, send a reminder' does not need intelligence — it needs reliability.
If the input is unpredictable — a voicemail, a photo, a rambling text message — that is where AI earns its place.
Why the order matters
Teams often reach for AI to solve a problem that is really an unwritten rule. The result is an expensive, non-deterministic solution to a deterministic problem.
Map the rules first. What remains is the genuine AI surface, and it is usually smaller and more valuable than expected.