Public evidence

engineering.process.capability

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

Open calculator API Capability Download JSON CVP Manifest Reproduce MCP Review policy

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · Design-stage Cp, Cpk, Cpu, Cpl from stated μ and σ + O3 mpmath tabulated Cp/Cpk. Two-sided USL > LSL.· Stated μ,σ two-sided. Not Pp/Ppk, not P/T, not Monte Carlo. O3 tabulated vectors only. · Protocol · Schema · Production report

Declared partition coverage: PASS · 6/6 declared partitions (centered, off-center-high, off-center-low, negative-cpk, alias, invalid-domain)
Versions: Calculation 1.0.0 · CVP protocol 1.0.0-proposed · Evidence 2026-09-16.o2-o3
Verification revision: 2026-09-16.o2-o3 · 3/3 property · digest d45618000fe2

Verification

Legacy regression suite: 5/5 calculation tests · Production surface contract 4/4

Three distinct suites: educational examples on the calculator page, this legacy regression count (5/5 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-16.o2-o3. Calculation version 1.0.0. CVP 1.0.0-proposed. 5/5 golden · 2/2 CVP boundary · 6/6 invalid · 3/3 property · 2/2 metamorphic · 8/8 O3 · 4/4 cross-interface · 4/4 CVP contract. digest d45618000fe2. O2: design-stage Cp/Cpk/Cpu/Cpl vs separate-module identities (≤2 ULP). Not Pp/Ppk, not Cpm, not P/T=1/Cp, not Monte Carlo, not an in-control SPC study. ≤2 ULP vs O3 applies only to the published tabulated Cp/Cpk vectors (centered, off-center, negative Cpk, aliases, σ=2, shifted limits, tight). It is not a whole-domain guarantee and does not cover Pp/Ppk, Cpm, P/T, or Monte Carlo simulated indices.

Golden (oracle-backed) 5 / 5
CVP boundary 2 / 2
Invalid input 6 / 6
Property 3 / 3
Metamorphic 2 / 2
O3 high-precision 8 / 8
Cross-interface 4 / 4
CVP contract 4 / 4
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
Verified scope Design-stage Cp, Cpk, Cpu, Cpl from stated μ and σ + O3 mpmath tabulated Cp/Cpk. Two-sided USL > LSL.
Assurance Engineering
Deferred Not Pp/Ppk from a sample, not Cpm/Cpmk, not P/T = 1/Cp, not Monte Carlo simulated indices, not in-control SPC, and not a Cp≥1.33 verdict.

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS

Fingerprint sha256:a1a60218799bb43689a9dedca524e31c07f128d905e389b519a0c93fbe7347c5

Input schema sha256:1fded02ee1287a641eb5645f574818b51c4a1e06e236456287f2b5303ffc5af9 · Output schema sha256:2c5af670b13dd55f0e6913e4c9a824fb041cece92dda81a6538a4698b5bf506b · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: process-capability
Engine: process-capability
Engine build: 2026-09-16
Evidence core: 2026-09-16T04:33:21.940Z
Rendered: 2026-09-16T22:03:43.732Z
Last reviewed: —

Assumptions

Design-stage from stated μ and σ — not in-control SPC
Not Monte Carlo simulated indices
Two-sided limits; USL > LSL
Normal-theory 6σ / 3σ formulas

Limitations

Design-stage indices from μ and σ — not measured in-control SPC
Not Monte Carlo simulated Cp/Cpk
Two-sided LSL/USL required; USL must be greater than LSL

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

NIST Engineering Statistics Handbook — Process Capability — 6.1.6.1 Cp (process capability index)
Supports: Cp = (USL − LSL) / (6σ) from a stated process standard deviation
NIST Engineering Statistics Handbook — Process Capability — 6.1.6.2 Cpk
Supports: Cpk = min(Cpu, Cpl) accounts for process centering; Cpu=(USL−μ)/(3σ), Cpl=(μ−LSL)/(3σ)

Legacy published checks

Golden and boundary cases from the legacy Evidence JSON. CVP property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the Manifest — including SKIP when a suite has no vectors.

ID	Kind	Status	Detail
`golden-cpk-center`	golden	pass	Expected Cp=2 · Cpk=2 · Actual Cp=2 · Cpk=2 · Cpu=2 · Cpl=2 · lsl=0 · usl=12 · mu=6 · sigma=1
`boundary-cpk-sigma`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-cpk-limits`	boundary	pass	Expected INVALID_INPUT · Actual INVALID_INPUT
`property-cpk-center`	property	pass	2
`property-cpk-shift`	property	pass	4/3