1
Microsoft SDD
Seven phases — Constitution, Specify, Clarify, Plan, Tasks, Implement, Validate — in which intent is captured before code is generated. Spec quality equals output quality is asserted, not yet measured.
The third weave · 21 October 2026
Spec quality becomes spec confidence.
The blueprints already answer what evidence an AI-infused system needs, and whether that evidence justifies trust. What they did not yet have is an account of systems generated from a spec. Spec-Driven Assurance is that account: every Spec-Driven Development artifact carries an assurance obligation and a Confidence Engineering question.
7 phases·9 weave notes·5th anchor·4 templates·8 measures
SDD phases across the evidence layers
- 1ConstitutionIntent
- 2SpecifyIntent
- 3ClarifyIntent
- 4PlanVerification
- 5TasksVerification
- 6ImplementExploration
- 7ValidateRuntime
Spine owns Constitution through Clarify, and Validate. Builders own Plan, Tasks, and Implement. NFR runs as a parallel rail from constitution to monitor.
The operating rule
Three inputs, one extension.
AI Assurance answers what evidence is required. Confidence Engineering answers whether that evidence justifies trust. Spec-Driven Development supplies the missing front end: the spec as the shared source of truth for humans and AI.
2
The blueprints
AI Assurance, Confidence Engineering, and the Crosswalk. One operating rule already: every AI Assurance artifact carries a Confidence Engineering question.
3
The spine
Define, analyse, trace and verify, hand over, assure. It specifies and measures. It does not build, and it is not a compliance management system.
ExtendedEvery SDD artifact carries an assurance obligation (the what) and a Confidence Engineering question (how we know).
Five conclusions
What the extension changes.
Upstream
Leverage moves upstream
The AI Assurance lifecycle is not replaced. Scoping and test design fold into the spec and the plan — where the Intent Layer said the most cost-effective gap-closing investment was.
Measure
Spec quality becomes spec confidence
DeFOSPAM lens counts, IEEE 830 characteristics, and Planguage quantification put an interval on what Spec-Driven Development only asserts. Recorded at generation time and compared with output confidence later, spec quality equals output quality becomes a testable claim.
Criteria
Measurable means a distribution
For AI-touched behaviour the criterion is a 0–2 rubric over a named, versioned set, under stated conditions, with an interval. Binary pass/fail only where Design AI Testing already says it belongs.
Implement
The Two Unknowns become literal
Generated tests are not evidence for generated code. Evidence must come from outside the generator’s distribution — Level 3 human-in-the-loop, a persona portfolio, operational telemetry — with provenance distinct and logged.
Validate
Validate opens a stream
Monitoring as Continuous Evaluation already inverted the lifecycle. Converge re-reads the stream as a regression delta, and the Confidence Engineer owns the verdict.
Anchor
A5 touches every layer
An executable, quantified specification is the primary artifact. A5 is primary on the Intent Layer and secondary on every other layer — the first anchor to close Anchors × Evidence Layers end to end.