FAILURE MAP
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FA-12266 / Power metering accounting / Open access

Independent feeder peaks inflate the site demand register · case 01

Independent feeder peaks inflate the site demand register.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The sum of each feeder maximum combines peaks that occurred at different times.

VERIFIED REPAIR

Sum synchronized feeder readings per interval before finding the maximum.

Unsuccessful approach: Taking the largest feeder reading avoids that sum but omits simultaneous demand from other feeders.

Case contract

Rows contain simultaneous nonnegative demand from each feeder for equal intervals. Return the maximum site sum over rows, or zero for no intervals. Rows are rectangular and nonempty.

Why this case matters

Meter settlement depends on explicit register and tariff policies; this controlled model makes that policy observable.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(rows):
    return sum(max(col) for col in zip(*rows)) if rows else 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('noncoincident peaks', solve([[5*N,N],[N,5*N]]),6*N)
check('coincident loads', solve([[3*N,4*N]]),7*N)
check('one feeder', solve([[N],[2*N]]),2*N)
check('idle site', solve([[0,0]]),0)
check('no intervals', solve([]),0)
check('smaller feeders together beat peak', solve([[5*N,0],[3*N,3*N]]),6*N)
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 fixtureActualExpectedOutcome
noncoincident peaks106Failed
coincident loads77Passed
one feeder22Passed
idle site00Passed
no intervals00Passed
smaller feeders together beat peak86Failed

SHA-256 / d2ab9e44b579654311110f282c728dfeaf640899a8d9a3d8615aa1d703367e0a

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(rows):
    return max((max(row) for row in rows),default=0)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('noncoincident peaks', solve([[5*N,N],[N,5*N]]),6*N)
check('coincident loads', solve([[3*N,4*N]]),7*N)
check('one feeder', solve([[N],[2*N]]),2*N)
check('idle site', solve([[0,0]]),0)
check('no intervals', solve([]),0)
check('smaller feeders together beat peak', solve([[5*N,0],[3*N,3*N]]),6*N)
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 fixtureActualExpectedOutcome
noncoincident peaks56Failed
coincident loads47Failed
one feeder22Passed
idle site00Passed
no intervals00Passed
smaller feeders together beat peak56Failed

SHA-256 / bd221f5b499fae1f6801751e737baea03fcab732607c31b9b2691a31afe14541

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(rows):
    return max((sum(row) for row in rows),default=0)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('noncoincident peaks', solve([[5*N,N],[N,5*N]]),6*N)
check('coincident loads', solve([[3*N,4*N]]),7*N)
check('one feeder', solve([[N],[2*N]]),2*N)
check('idle site', solve([[0,0]]),0)
check('no intervals', solve([]),0)
check('smaller feeders together beat peak', solve([[5*N,0],[3*N,3*N]]),6*N)
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 fixtureActualExpectedOutcome
noncoincident peaks66Passed
coincident loads77Passed
one feeder22Passed
idle site00Passed
no intervals00Passed
smaller feeders together beat peak66Passed

SHA-256 / 7c94ea14134146d042653c660e0eb9cfdd0733e326339fd210601099f22ae367

Verification & scope

Simplified integer-energy accounting model; no hardware protocol, legal tariff, measurement uncertainty, or live grid behavior is represented. 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 2026-09-29T14:38:55.396120+00:00.

Case digest / dc8005964187ca4d717f699a8ea3f191bdccb33a5362f464888a94e115e68ba2