ModelRefs / Plan-and-Execute — Prompt Pattern
Plan-and-Execute — Prompt Pattern
Plan all steps upfront, then execute them with a cheaper model. Use a strong model to produce a numbered plan; a cheaper model executes each step.
Overview
Use a strong model to produce a numbered plan; a cheaper model executes each step. Reduces drift on long horizons.
When to use it: Long-horizon tasks where ReAct drifts.
Pattern details
| Pattern class | agent |
|---|---|
| Difficulty | advanced |
| Also known as | planner-executor, plan-then-do |
| Last reviewed | 2026-06-07 |
Known failure modes
- Rigid plan — Plan made with wrong assumptions. Mitigation: Allow replanning between steps.
When not to use it
- Forcing this on short tasks (overhead > benefit).
Continue your research
Use these connected ModelRefs sections to compare alternatives, inspect implementation paths, and review the evidence and governance boundaries relevant to Plan-and-Execute — Prompt Pattern.
Frequently asked questions
When should I use the Plan-and-Execute prompt pattern?
Long-horizon tasks where ReAct drifts.
What are common failure modes of Plan-and-Execute?
Rigid plan
Does Plan-and-Execute work across models?
Yes when the anatomy is preserved — see model compatibility matrix on the pattern page.