FA-95321 / Warehouse slotting and bin packing / Open access

Honeycombing: later line replaces SKU total · case 01

Adjustment lines replace the SKU quantity instead of netting against it.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Per-SKU pallets are overwritten by each line.

VERIFIED REPAIR

Sum all lines for a SKU before sizing lanes.

Unsuccessful approach: Keeping only the first line ignores later receipts and adjustments.

Case contract

skus [[sku, pallets]] where lines may be adjustments (negative) and are netted per SKU. Each SKU with net pallets > 0 needs ceil(pallets/depth) single-SKU lanes. Honeycomb loss = lanes*depth - pallets. Utilization bp = floor((positions-loss)*10000/positions), 0 with no positions. Status OVER when lanes > available. Return [lanes, loss, util_bp, status].

Why this case matters

Deep-lane storage loses positions when lanes cannot be mixed across SKUs.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(skus, depth, available):
    merged = {}
    for sku, pallets in skus:
        merged[sku] = pallets
    lanes = 0
    loss = 0
    for sku, pallets in merged.items():
        if pallets <= 0:
            continue
        n = -(-pallets // depth)
        lanes += n
        loss += n * depth - pallets
    positions = lanes * depth
    util = (positions - loss) * 10000 // positions if positions else 0
    return [lanes, loss, util, 'OVER' if lanes > available else 'OK']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 8', [[['C', 2], ['A', 8]], 3, 2], [4, 2, 8333, 'OVER']]], [['generated mix 9', [[['D', 8], ['D', -3], ['C', 1], ['A', 3], ['C', 8]], 3, 8], [6, 1, 9444, 'OK']], ['generated mix 5', [[['B', 5], ['C', 1], ['A', 5], ['A', 3], ['B', 4]], 2, 8], [10, 2, 9000, 'OVER']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['generated mix 11', [[['C', 4], ['C', 8]], 5, 2], [3, 3, 8000, 'OVER']], ['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']]], [['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']], ['generated mix 13', [[['B', -3], ['B', 9], ['C', 3], ['B', 2]], 5, 6], [3, 4, 7333, 'OK']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 22', [[['A', -1], ['B', 1], ['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 30', [[['D', 8]], 5, 2], [2, 2, 8000, 'OK']]], [['generated mix 39', [[['D', 1], ['D', 1], ['B', 5]], 5, 2], [2, 3, 7000, 'OK']], ['generated mix 20', [[['A', 2], ['D', -1], ['C', 8], ['D', 2], ['B', 1]], 2, 2], [7, 2, 8571, 'OVER']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['generated mix 32', [[['B', 1], ['D', 9], ['D', 4], ['D', 2], ['D', 8]], 4, 3], [7, 4, 8571, 'OVER']], ['generated mix 41', [[['A', 8], ['B', -3], ['A', 9], ['C', 9], ['B', -3]], 3, 2], [9, 1, 9629, 'OVER']]], [['generated mix 49', [[['B', 5], ['C', 1], ['C', 9], ['D', 9], ['C', 3]], 3, 4], [10, 3, 9000, 'OVER']], ['generated mix 35', [[['C', -1], ['C', 2]], 3, 6], [1, 2, 3333, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 43', [[['B', -3]], 3, 6], [0, 0, 0, 'OK']], ['generated mix 52', [[['C', 4], ['C', 8], ['C', 5]], 4, 6], [5, 3, 8500, 'OK']]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
merge lines	`[1, 2, 5000, 'OK']`	`[2, 3, 6250, 'OK']`	Failed
adjustment nets out	`[1, 3, 2500, 'OK']`	`[1, 3, 2500, 'OK']`	Passed
mixed	`[4, 3, 8125, 'OK']`	`[4, 3, 8125, 'OK']`	Passed
over	`[3, 3, 7500, 'OVER']`	`[3, 3, 7500, 'OVER']`	Passed
floor util	`[1, 1, 6666, 'OK']`	`[1, 1, 6666, 'OK']`	Passed
lanes equal available	`[2, 0, 10000, 'OK']`	`[2, 0, 10000, 'OK']`	Passed
empty	`[0, 0, 0, 'OK']`	`[0, 0, 0, 'OK']`	Passed
generated mix 8	`[4, 2, 8333, 'OVER']`	`[4, 2, 8333, 'OVER']`	Passed

SHA-256 / 51a97b20ce0f1118015446dc3b16f542495dc7578e666e9cc6e1a60a5ab902fe

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(skus, depth, available):
    merged = {}
    for sku, pallets in skus:
        merged.setdefault(sku, pallets)
    lanes = 0
    loss = 0
    for sku, pallets in merged.items():
        if pallets <= 0:
            continue
        n = -(-pallets // depth)
        lanes += n
        loss += n * depth - pallets
    positions = lanes * depth
    util = (positions - loss) * 10000 // positions if positions else 0
    return [lanes, loss, util, 'OVER' if lanes > available else 'OK']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 8', [[['C', 2], ['A', 8]], 3, 2], [4, 2, 8333, 'OVER']]], [['generated mix 9', [[['D', 8], ['D', -3], ['C', 1], ['A', 3], ['C', 8]], 3, 8], [6, 1, 9444, 'OK']], ['generated mix 5', [[['B', 5], ['C', 1], ['A', 5], ['A', 3], ['B', 4]], 2, 8], [10, 2, 9000, 'OVER']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['generated mix 11', [[['C', 4], ['C', 8]], 5, 2], [3, 3, 8000, 'OVER']], ['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']]], [['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']], ['generated mix 13', [[['B', -3], ['B', 9], ['C', 3], ['B', 2]], 5, 6], [3, 4, 7333, 'OK']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 22', [[['A', -1], ['B', 1], ['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 30', [[['D', 8]], 5, 2], [2, 2, 8000, 'OK']]], [['generated mix 39', [[['D', 1], ['D', 1], ['B', 5]], 5, 2], [2, 3, 7000, 'OK']], ['generated mix 20', [[['A', 2], ['D', -1], ['C', 8], ['D', 2], ['B', 1]], 2, 2], [7, 2, 8571, 'OVER']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['generated mix 32', [[['B', 1], ['D', 9], ['D', 4], ['D', 2], ['D', 8]], 4, 3], [7, 4, 8571, 'OVER']], ['generated mix 41', [[['A', 8], ['B', -3], ['A', 9], ['C', 9], ['B', -3]], 3, 2], [9, 1, 9629, 'OVER']]], [['generated mix 49', [[['B', 5], ['C', 1], ['C', 9], ['D', 9], ['C', 3]], 3, 4], [10, 3, 9000, 'OVER']], ['generated mix 35', [[['C', -1], ['C', 2]], 3, 6], [1, 2, 3333, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 43', [[['B', -3]], 3, 6], [0, 0, 0, 'OK']], ['generated mix 52', [[['C', 4], ['C', 8], ['C', 5]], 4, 6], [5, 3, 8500, 'OK']]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
merge lines	`[1, 1, 7500, 'OK']`	`[2, 3, 6250, 'OK']`	Failed
adjustment nets out	`[2, 4, 5000, 'OVER']`	`[1, 3, 2500, 'OK']`	Failed
mixed	`[4, 3, 8125, 'OK']`	`[4, 3, 8125, 'OK']`	Passed
over	`[3, 3, 7500, 'OVER']`	`[3, 3, 7500, 'OVER']`	Passed
floor util	`[1, 1, 6666, 'OK']`	`[1, 1, 6666, 'OK']`	Passed
lanes equal available	`[2, 0, 10000, 'OK']`	`[2, 0, 10000, 'OK']`	Passed
empty	`[0, 0, 0, 'OK']`	`[0, 0, 0, 'OK']`	Passed
generated mix 8	`[4, 2, 8333, 'OVER']`	`[4, 2, 8333, 'OVER']`	Passed

SHA-256 / f62b187f7177974ba55277f25c10fa247cc089768608779ee36a8c435097663a

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(skus, depth, available):
    merged = {}
    for sku, pallets in skus:
        merged[sku] = merged.get(sku, 0) + pallets
    lanes = 0
    loss = 0
    for sku, pallets in merged.items():
        if pallets <= 0:
            continue
        n = -(-pallets // depth)
        lanes += n
        loss += n * depth - pallets
    positions = lanes * depth
    util = (positions - loss) * 10000 // positions if positions else 0
    return [lanes, loss, util, 'OVER' if lanes > available else 'OK']
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 8', [[['C', 2], ['A', 8]], 3, 2], [4, 2, 8333, 'OVER']]], [['generated mix 9', [[['D', 8], ['D', -3], ['C', 1], ['A', 3], ['C', 8]], 3, 8], [6, 1, 9444, 'OK']], ['generated mix 5', [[['B', 5], ['C', 1], ['A', 5], ['A', 3], ['B', 4]], 2, 8], [10, 2, 9000, 'OVER']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['generated mix 11', [[['C', 4], ['C', 8]], 5, 2], [3, 3, 8000, 'OVER']], ['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']]], [['generated mix 19', [[['A', 5], ['A', 3], ['D', -3], ['C', 8], ['D', 1]], 5, 1], [4, 4, 8000, 'OVER']], ['generated mix 13', [[['B', -3], ['B', 9], ['C', 3], ['B', 2]], 5, 6], [3, 4, 7333, 'OK']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['adjustment nets out', [[['A', 3], ['A', -3], ['B', 1]], 4, 1], [1, 3, 2500, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['generated mix 22', [[['A', -1], ['B', 1], ['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 30', [[['D', 8]], 5, 2], [2, 2, 8000, 'OK']]], [['generated mix 39', [[['D', 1], ['D', 1], ['B', 5]], 5, 2], [2, 3, 7000, 'OK']], ['generated mix 20', [[['A', 2], ['D', -1], ['C', 8], ['D', 2], ['B', 1]], 2, 2], [7, 2, 8571, 'OVER']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['floor util', [[['A', 2]], 3, 1], [1, 1, 6666, 'OK']], ['lanes equal available', [[['A', 8]], 4, 2], [2, 0, 10000, 'OK']], ['generated mix 32', [[['B', 1], ['D', 9], ['D', 4], ['D', 2], ['D', 8]], 4, 3], [7, 4, 8571, 'OVER']], ['generated mix 41', [[['A', 8], ['B', -3], ['A', 9], ['C', 9], ['B', -3]], 3, 2], [9, 1, 9629, 'OVER']]], [['generated mix 49', [[['B', 5], ['C', 1], ['C', 9], ['D', 9], ['C', 3]], 3, 4], [10, 3, 9000, 'OVER']], ['generated mix 35', [[['C', -1], ['C', 2]], 3, 6], [1, 2, 3333, 'OK']], ['empty', [[], 4, 1], [0, 0, 0, 'OK']], ['mixed', [[['A', 5], ['B', 8]], 4, 10], [4, 3, 8125, 'OK']], ['merge lines', [[['A', 3], ['A', 2]], 4, 5], [2, 3, 6250, 'OK']], ['over', [[['A', 9]], 4, 2], [3, 3, 7500, 'OVER']], ['generated mix 43', [[['B', -3]], 3, 6], [0, 0, 0, 'OK']], ['generated mix 52', [[['C', 4], ['C', 8], ['C', 5]], 4, 6], [5, 3, 8500, 'OK']]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
merge lines	`[2, 3, 6250, 'OK']`	`[2, 3, 6250, 'OK']`	Passed
adjustment nets out	`[1, 3, 2500, 'OK']`	`[1, 3, 2500, 'OK']`	Passed
mixed	`[4, 3, 8125, 'OK']`	`[4, 3, 8125, 'OK']`	Passed
over	`[3, 3, 7500, 'OVER']`	`[3, 3, 7500, 'OVER']`	Passed
floor util	`[1, 1, 6666, 'OK']`	`[1, 1, 6666, 'OK']`	Passed
lanes equal available	`[2, 0, 10000, 'OK']`	`[2, 0, 10000, 'OK']`	Passed
empty	`[0, 0, 0, 'OK']`	`[0, 0, 0, 'OK']`	Passed
generated mix 8	`[4, 2, 8333, 'OVER']`	`[4, 2, 8333, 'OVER']`	Passed

SHA-256 / 3c8321a44713310ab2983dd716f410c0762294b82496d49f15b24b05f4e0374c

Verification & scope

Stipulated single-SKU lane policy. 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 2026-09-29T14:52:12.606279+00:00.

Case digest / 5f5256cd4e638100ccd696d81aa60bfa3c63421675b05087727685395b9e141c