ASME V&V 40 · NASA-STD-7009B · ISO 42001 · Open source · Apache-2.0
An open-source way to package model credibility evidence so a reviewer can verify it without reading 200 pages of prose.
The problem
Reviewers don't reject your simulation. They reject your evidence package. Standards tell you what to assess. Your tools capture what ran. Neither captures why you believe it, and that's where submissions stall.
C1 · PACKAGES
Your credibility evidence becomes a portable, signed object you hand a reviewer. Ed25519 + SHA-256. Tool-independent. Tamper-evident.
C2 · DETECTS GAPS
Forward-chaining rules catch missing UQ and unsupported claims. Surfaces compound risks no standalone SPARQL query can find.
C3 · COMPARES
Score two published records under one catalog version and compare what evidence each one carries. Page 3 does this.
What a package binds
Requirement
bindsRequirement
Claim
bindsClaim
Model
bindsModel
Datasets2
bindsDataset
Context of use
hasContextOfUse
Credibility factors13
hasCredibilityFactor
Validation results6
hasValidationResult
Decision record
hasDecisionRecord
A package binds all of these in one signed object. The counts above are this record's, and page 2 sets them out in full.
What follows
Page 2
The record. Source paper, context of use, model risk, and how the 13 V&V 40 factors were assessed.
Page 3
The findings. What the rule engine flagged, the decision as encoded, integrity, and a comparison.
This document applies the tool to one published paper. It reports what that record contains. It is not an assessment of the modeling work, and it takes no position on regulatory review.
Why it might fit you
Works in medical device (ASME V&V 40), aerospace (NASA-STD-7009B), and AI management systems (ISO 42001) today. Runs locally, so evidence never leaves your environment. Sits alongside your PLM, SPDM, or model registry, and it doesn't replace them.
Zero install
codespaces.new/
cloudronin/uofa
On your machine
pip install uofa
uofa setup
Worked example
uofa.net/demo
ASME V&V 40 · Case record · Catalog core@0.5.0 + vv40@0.5.0
The Nagaraja et al. (2024) assessment, encoded as a signed Unit of Assurance package and scored by the weakener rule engine.
Source record
Nagaraja S, Loughran G, Baumann AP, Kartikeya K, Horner M. “Establishing finite element model credibility of a pedicle screw system under compression-bending: An end-to-end example of the ASME V&V 40 standard.” Methods 225 (2024) 74–88.
https://doi.org/10.1016/j.ymeth.2024.03.003
Context of use, as encoded
FEA predicts construct stiffness, yield force, and force at 40 mm displacement for the non-cannulated 7.5 mm pedicle screw design under ASTM F1717 static compression-bending. Validated by direct comparison to bench testing (N=11 constructs across two laboratories). Model influence MEDIUM (testing confirms results); decision consequence MEDIUM (pedicle screw fracture leads to revision surgery, not death). Package node nagaraja/cou/cou1-noncannulated
Model risk, as encoded
Model influence
Medium
Decision consequence
Medium
Model risk level
3
Assurance level
Medium
Device class
Class II
Model influence and decision consequence are the two components the record gives as drivers of model risk. Both are recorded at Medium.
Factor coverage, 13 of 13 assessed
The published record reports every factor in the ASME V&V 40 Table 5-1 set. 12 factors reach their required level. Values show achieved level against required level.
| Software quality assurance | 3 / 3 |
| Numerical code verification | 3 / 3 |
| Discretization error | 2 / 2 |
| Numerical solver error | 3 / 3 |
| Use error | 3 / 3 |
| Model form | 2 / 2 |
| Model inputs | 2 / 2 |
| Test samples | 2 / 2 |
| Test conditions | 1 / 3 |
| Equivalency of input parameters | 3 / 3 |
| Output comparison | 3 / 3 |
| Relevance of the quantities of interest | 3 / 3 |
| Relevance of the validation activities to the COU | 3 / 3 |
$ uofa check --build packs/vv40/examples/nagaraja/cou1/uofa-nagaraja-cou1.jsonld ══ C2: SHACL profile validation ══ ✓ SHACL validation Conforms ══ C1: Integrity verification (hash + signature) ══ ✓ Hash match ✓ Signature valid ══ C3: Jena rule engine ══ SUMMARY: 19 weakener(s) detected ───────────────────────────────── High: 19 ⚠ W-AL-01 [High] 6 hits ⚠ W-AR-05 [High] 6 hits ⚠ W-EP-02 [High] 6 hits ⚠ W-ON-02 [High] 1 hit
Weakeners detected
A weakener is a condition under which stated evidence does not support the claim it is offered for. It is a property of the record as published. It is not a defect in the modeling work.
| Pattern | Name | Severity | Hits | Attaches to | Finding |
|---|---|---|---|---|---|
| W-AL-01 | Aleatory uncertainty uncharacterized | High | 6 | 6 validation results | No uncertainty quantification is linked to the validation result node. |
| W-AR-05 | Comparator source absent | High | 6 | 6 validation results | No comparator data source is linked from the validation result node. |
| W-EP-02 | Generation activity missing | High | 6 | 6 validation results | No generating activity is recorded for the validation result node. |
| W-ON-02 | Validity boundary undocumented | High | 1 | cou1-noncannulated | The context of use carries no applicability constraint and no operating envelope. |
The package records uncertainty quantification and sensitivity analysis at the package level, and it carries validation results for both. W-AL-01 fires on all six validation results because no uncertainty quantification is linked from the individual validation result nodes. The rule reads the link rather than the package flag.
Decision record, as encoded
Accepted. Model accuracy met pre-established criterion of <10% difference between FEA and experiment for all three QoIs (stiffness 1.5% E/D, yield load 1.1% E/D, force at 40 mm 1.3% E/D). Critical stress location (rod midshaft) matched experimental failure mode. Test-conditions factor shortfall (achievedLevel 1 vs requiredLevel 3) is acknowledged and offset by N=11 sample size which exceeds typical spinal-device testing recommendations. Credibility assessment team · decided 2024-03-08
Offset rationale, test conditions
Test-conditions factor shortfall (achievedLevel 1 vs requiredLevel 3) — single ASTM F1717 static compression-bending condition — is offset by N=11 experimental constructs across two laboratories, which exceeds the typical spinal-device testing sample size convention. Nagaraja et al. (2024) §4 acknowledges the limitation explicitly and treats the larger sample size as compensating evidence for the narrow loading-condition coverage. Package node nagaraja/decision/cou1-overall/offset/test-conditions
Comparison at the same catalog version
Two published records scored under catalog core@0.5.0 + vv40@0.5.0. The counts describe how completely each record documents its evidence. They do not rank the papers or the teams.
| Record | Factors | Firings | Patterns | Severity |
|---|---|---|---|---|
| Nagaraja COU1 | 13 / 13 | 19 | 4 | High 19 |
| Morrison COU1 | 13 / 13 | 11 | 5 | High 10, Medium 1 |
| Morrison COU2 | 13 / 13 | 18 | 6 | Critical 9, High 7, Medium 2 |
SHACL profile
✓ Conforms · ProfileComplete
Hash
✓ Match · SHA-256
Signature
✓ Valid · Ed25519
Package hash
sha256:c0c3c30b766833b5581cea440871dfeae07e4745dbd6d55fd47797fff27e2727
Reproduce every number on these pages
$ uofa check --build packs/vv40/examples/nagaraja/cou1/uofa-nagaraja-cou1.jsonld