FA-12381 / Manufacturing workflow integrity / Open access

Duplicate samples mask an unqualified mold cavity · case 01

Duplicate samples mask an unqualified mold cavity.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The first-article gate uses sample count as a proxy for cavity coverage.

VERIFIED REPAIR

Require a passing first article for each active cavity, using its latest sample.

Unsuccessful approach: Checking a historical pass per cavity ignores a later failed sample.

Case contract

Active cavity IDs are unique. Chronological samples are (cavity, passed) pairs. Gate opens iff each active cavity latest sample passes; inactive cavities are irrelevant.

Why this case matters

A deterministic manufacturing record model isolates this workflow defect before equipment or enterprise integration.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(active, samples):
    return sum(ok for cavity, ok in samples) >= len(active)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
a = list(range(N+1))
good = [(i, True) for i in a]
check('complete cavity coverage', solve(a, good), True)
check('duplicates hide missing cavity', solve(a, [(0, True)] * (N+1)), False)
check('later cavity failure', solve(a, good + [(N, False)]), False)
check('successful retest', solve(a, [(N, False)] + good), True)
check('inactive failure ignored', solve(a, good + [(N+2, False)]), True)
check('no active cavities', solve([], []), True)
check('no samples', solve(a, []), False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
complete cavity coverage	`True`	`True`	Passed
duplicates hide missing cavity	`True`	`False`	Failed
later cavity failure	`True`	`False`	Failed
successful retest	`True`	`True`	Passed
inactive failure ignored	`True`	`True`	Passed
no active cavities	`True`	`True`	Passed
no samples	`False`	`False`	Passed

SHA-256 / 0e9e90dfe838354e08493fc4f733bad3e77a6e65afb0da546622305b580caaae

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(active, samples):
    return all(any(c == cavity and ok for c, ok in samples) for cavity in active)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
a = list(range(N+1))
good = [(i, True) for i in a]
check('complete cavity coverage', solve(a, good), True)
check('duplicates hide missing cavity', solve(a, [(0, True)] * (N+1)), False)
check('later cavity failure', solve(a, good + [(N, False)]), False)
check('successful retest', solve(a, [(N, False)] + good), True)
check('inactive failure ignored', solve(a, good + [(N+2, False)]), True)
check('no active cavities', solve([], []), True)
check('no samples', solve(a, []), False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
complete cavity coverage	`True`	`True`	Passed
duplicates hide missing cavity	`False`	`False`	Passed
later cavity failure	`True`	`False`	Failed
successful retest	`True`	`True`	Passed
inactive failure ignored	`True`	`True`	Passed
no active cavities	`True`	`True`	Passed
no samples	`False`	`False`	Passed

SHA-256 / ab347352aa932c9b493360520ef7c842f513d54edbe1b2c3a7b7058ed28529e4

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(active, samples):
    latest = dict(samples)
    return all(latest.get(cavity, False) for cavity in active)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
a = list(range(N+1))
good = [(i, True) for i in a]
check('complete cavity coverage', solve(a, good), True)
check('duplicates hide missing cavity', solve(a, [(0, True)] * (N+1)), False)
check('later cavity failure', solve(a, good + [(N, False)]), False)
check('successful retest', solve(a, [(N, False)] + good), True)
check('inactive failure ignored', solve(a, good + [(N+2, False)]), True)
check('no active cavities', solve([], []), True)
check('no samples', solve(a, []), False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
complete cavity coverage	`True`	`True`	Passed
duplicates hide missing cavity	`False`	`False`	Passed
later cavity failure	`False`	`False`	Passed
successful retest	`True`	`True`	Passed
inactive failure ignored	`True`	`True`	Passed
no active cavities	`True`	`True`	Passed
no samples	`False`	`False`	Passed

SHA-256 / c1824eec694ba8093b8125bdce23cc9b6d5c8bb71f6b073487e8dd75833cfe65

Verification & scope

Offline policy model only; no physical equipment, regulatory certification, or concurrent transaction claims. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:56.258879+00:00.

Case digest / fc45f748cffd47fd619315fdef56f1aaf1655d1938c1ee546b3052f00898d921