A one-page companion to Does This Decision Actually Need a Large Language Model?. Print it and keep it at the desk.
Before you choose a model, look at the shape of the answer the step needs. Ask this of each step, not once for the whole process.
| What the work requires | A reasonable place to start |
|---|---|
| A known calculation, threshold, match, or rule | Deterministic automation (formula, Power Query, SQL, Python) |
| A bounded choice among answers you can list in advance | Decision model (or another classification approach) |
| A score or probability used to prioritize | Decision model or a predictive model trained on your history |
| Interpreting or writing open-ended language | Large language model (LLM), validated |
| Material professional judgment or accountability | A qualified person |
This is a starting point, not a hierarchy. Real workflows combine these, and some steps can be solved more than one way. The table describes what runs the step each month. AI can still help build and maintain any of these, including the deterministic one (AI Helped Me Build It. AI Does Not Have to Run It.).
| # | Question | If yes |
|---|---|---|
| 1 | Is the rule known? Could you write it as an IF statement? |
Encode the rule, and let your AI co-pilot help you build, test, and maintain it. No model needed to run it. |
| 2 | Can the outcomes be listed in advance? Five reason codes, six queues, a 1-to-4 scale? | A decision model may fit. Add an “other” or “cannot tell” option. |
| 3 | Is open-ended language really needed? Must the answer be written, or only chosen? | If it must be written, an LLM earns its place. If only chosen, it probably doesn’t. |
| 4 | What is the minimum evidence? Which fields does the step actually need to see? | Send only those. The safest confidential field is the one you never provide. |
| 5 | Who owns the consequence? Approval, accounting treatment, a decision about a person? | A person keeps it. The model sorts; it does not approve. |
| *PythonMuse LLC | www.pythonmuse.com. Educational purposes only; not professional advice. Content licensed under CC BY-NC-SA 4.0.* |