Conventional software
Use deterministic rules, templates, queries, or calculations when they solve the task reliably.
What this pattern means
Use deterministic rules, templates, queries, or calculations when they solve the task reliably. Choose it because it is the least complex approach that satisfies the task—not because it uses the most capable model.
When it fits
- Inputs and rules are stable and complete.
- The same input should produce the same output.
- Correctness can be asserted with ordinary software tests.
When it does not fit
- The task needs interpretation of ambiguous natural language.
- The task needs synthesis across incomplete or changing evidence.
Required controls
- Validate input types.
- Test edge cases and preserve an audit trail for consequential outputs.
Autonomy limit
The maximum v1 autonomy is Bounded reversible action. A task-specific rule may impose a stricter cap.
Minimum evaluation
Use deterministic unit, integration, and boundary tests rather than subjective model grading.
Example
Calculate invoice totals from validated line items and tax rules.
Reassess conventional software whenever the purpose, evidence, data class, decision owner, or external-action boundary changes.