The lifecycle folds forward
Scoping and test design happen inside the spec and the plan. The AI Assurance lifecycle — Scoping, Design, Execution, Insights, Monitoring — is not replaced.
Section 2
The phase map
Each Spec-Driven Development phase placed against the AI Assurance lifecycle, the Confidence Engineering evidence layers, and the stages of a specification spine.
| SDD phase | AI Assurance — the what | Confidence Engineering — how we know | Spine stage | Evidence layer |
|---|---|---|---|---|
| 1 Constitution | AI QA Scoping Plan; regulatory anchoring; guardrails named as assumptions; system type to framework | Regulations and the recursive standard; confidence as a scarce, governed resource | Define | Intent |
| 2 Specify | Scope questions answered inside the spec; coverage areas; scenarios; DeFOSPAM definitions, features, outcomes, scenarios | Spec confidence — IEEE 830 scores and DeFOSPAM counts with an interval | Define | Intent |
| 3 Clarify | Ambiguity and Missing lenses; known weak spots; system prompt; decoding parameters; the risk catalogue | What is not yet known is the risk signal. Markers are a register. No guessing. | Analyse | Intent |
| Criteria | Binary for deterministic flows; 0–2 rubric for open-ended output | Distributions with intervals under stated conditions | Analyse | Intent / NFR |
| 4 Plan | Test design framework; estimation; who to involve | Testable architecture; evals, baselines, and monitors planned as product components; the assurance gate | Analyse → Hand over | Verification infrastructure |
| 5 Tasks | Run instructions, prompt sets, HITL packages, red-team charters, technique-driven cases as [E] evidence tasks | Evidence budget allocated by risk; baseline sets and rubric exist before generation | Hand over | Verification infrastructure |
| 6 Implement | Model evals, system automation, user-level HITL; persona exploration of generated artifacts | Generated tests are not evidence for generated code; evaluator provenance distinct and logged | Builder → Trace & Verify | Exploration |
| 7 Validate | 0–2 rubric per coverage area; end report; regression deltas; monitoring and continuous validation | Distributions; validation opens the evidence stream; operational reality; the Confidence Engineer’s verdict | Trace & Verify → Assure | Runtime |
Three readings
How to use the map.
The evidence layers line up
Intent in phases 2–3, verification infrastructure in 4–5, exploration in 6, runtime in 7. NFR is a parallel rail from constitution to monitor.
The spine says who owns what
The contract is a handover pack down — specification, scenarios, measures, a constitution fragment, open clarifications — and an evidence pack up: distributions, deltas, plan and task identifiers, provenance, and a runtime signal.