FA-95131 / Warehouse slotting and bin packing / Open access

Re-slot plan: one move over budget · case 01

The plan contains one more move than the labour budget allows.

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

ROOT CAUSE

The budget check breaks only after the plan exceeds max_moves.

VERIFIED REPAIR

Stop accepting once the plan already holds max_moves moves.

Unsuccessful approach: Counting both moved SKUs and targets halves the effective budget.

Case contract

cands [[sku, from_slot, to_slot, weekly_picks, travel_from, travel_to]]. Weekly benefit = picks*(travel_from - travel_to); keep candidates with benefit >= move_cost; rank by benefit desc, sku, from, to. Greedily accept up to max_moves: each SKU moves once, each target is used once, and a target that is the from_slot of any candidate is occupied unless that slot was already vacated by an accepted move. Return [[sku, to_slot, benefit]].

Why this case matters

Periodic re-slotting moves SKUs whose velocity changed toward better locations.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(cands, move_cost, max_moves):
    occupied = {c[1] for c in cands}
    ranked = []
    for sku, frm, to, picks, tf, tt in cands:
        benefit = picks * (tf - tt)
        if benefit >= move_cost:
            ranked.append((-benefit, sku, frm, to))
    ranked.sort()
    plan = []
    moved = set()
    targets = set()
    vacated = set()
    for nb, sku, frm, to in ranked:
        if len(plan) > max_moves:
            break
        if sku in moved or to in targets:
            continue
        if to in occupied and to not in vacated:
            continue
        plan.append([sku, to, -nb])
        moved.add(sku)
        targets.add(to)
        vacated.add(frm)
    return plan
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 25', [[['K1', 'S3', 'S6', 10, 10, 5], ['K3', 'S7', 'S1', 10, 50, 5], ['K2', 'S3', 'S4', 40, 50, 20]], 200, 2], [['K2', 'S4', 1200], ['K3', 'S1', 450]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 6', [[['K3', 'S1', 'S3', 20, 50, 10], ['K3', 'S4', 'S7', 40, 50, 40]], 400, 2], [['K3', 'S3', 800]]], ['generated mix 14', [[['K3', 'S7', 'S4', 10, 10, 30], ['K4', 'S6', 'S3', 10, 50, 5], ['K2', 'S5', 'S6', 5, 30, 10]], 200, 3], [['K4', 'S3', 450]]]], [['generated mix 62', [[['K4', 'S4', 'S5', 10, 50, 5], ['K1', 'S3', 'S4', 40, 10, 20], ['K1', 'S5', 'S2', 20, 50, 30], ['K1', 'S7', 'S6', 10, 50, 20], ['K4', 'S3', 'S5', 40, 30, 40], ['K3', 'S4', 'S6', 20, 50, 10]], 200, 1], [['K3', 'S6', 800]]], ['generated mix 59', [[['K1', 'S3', 'S7', 40, 10, 30], ['K1', 'S2', 'S5', 40, 20, 20], ['K4', 'S2', 'S3', 10, 20, 10], ['K4', 'S3', 'S2', 10, 20, 40], ['K4', 'S5', 'S1', 40, 50, 30]], 0, 2], [['K4', 'S1', 800], ['K1', 'S5', 0]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 9', [[['K1', 'S6', 'S1', 20, 20, 20], ['K3', 'S5', 'S6', 40, 20, 20]], 0, 3], [['K1', 'S1', 0], ['K3', 'S6', 0]]], ['generated mix 17', [[['K1', 'S2', 'S6', 5, 20, 20], ['K2', 'S7', 'S1', 10, 50, 30]], 50, 3], [['K2', 'S1', 200]]]], [['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]], ['generated mix 42', [[['K3', 'S7', 'S2', 10, 20, 40], ['K1', 'S6', 'S2', 10, 20, 20], ['K2', 'S5', 'S2', 20, 30, 20], ['K4', 'S7', 'S4', 40, 50, 30]], 200, 2], [['K4', 'S4', 800], ['K2', 'S2', 200]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['generated mix 20', [[['K1', 'S3', 'S7', 5, 50, 40], ['K3', 'S4', 'S5', 20, 10, 10], ['K2', 'S6', 'S5', 5, 30, 30], ['K3', 'S2', 'S5', 40, 50, 20], ['K4', 'S5', 'S7', 10, 10, 30], ['K2', 'S5', 'S4', 40, 30, 5]], 0, 1], [['K1', 'S7', 50]]], ['generated mix 28', [[['K3', 'S4', 'S2', 10, 50, 30], ['K2', 'S1', 'S3', 10, 50, 30], ['K4', 'S1', 'S2', 20, 50, 5]], 400, 2], [['K4', 'S2', 900]]]], [['generated mix 30', [[['K2', 'S4', 'S5', 5, 30, 5], ['K4', 'S3', 'S1', 40, 50, 20], ['K2', 'S6', 'S1', 5, 20, 40]], 0, 1], [['K4', 'S1', 1200]]], ['generated mix 33', [[['K3', 'S5', 'S3', 40, 50, 5], ['K2', 'S4', 'S6', 10, 20, 10], ['K4', 'S5', 'S2', 5, 50, 5], ['K4', 'S6', 'S3', 5, 20, 40], ['K4', 'S4', 'S6', 40, 30, 30]], 200, 2], [['K3', 'S3', 1800], ['K4', 'S2', 225]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 32', [[['K2', 'S5', 'S1', 10, 30, 5], ['K2', 'S1', 'S3', 5, 10, 40], ['K3', 'S5', 'S4', 20, 10, 10], ['K4', 'S3', 'S5', 10, 50, 40], ['K2', 'S4', 'S6', 40, 10, 40]], 0, 3], []], ['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]]], [['generated mix 4', [[['K3', 'S4', 'S3', 10, 50, 10], ['K4', 'S4', 'S3', 20, 20, 20], ['K3', 'S4', 'S6', 40, 20, 20], ['K4', 'S7', 'S3', 20, 20, 20], ['K4', 'S1', 'S6', 20, 50, 20]], 0, 1], [['K4', 'S6', 600]]], ['generated mix 13', [[['K2', 'S2', 'S1', 10, 10, 5], ['K4', 'S5', 'S6', 40, 20, 40], ['K2', 'S4', 'S2', 40, 30, 40], ['K3', 'S2', 'S6', 40, 50, 10]], 50, 2], [['K3', 'S6', 1600], ['K2', 'S1', 50]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['generated mix 44', [[['K3', 'S5', 'S2', 40, 20, 30], ['K3', 'S6', 'S2', 5, 50, 5], ['K3', 'S2', 'S3', 10, 20, 20], ['K4', 'S3', 'S1', 20, 50, 20], ['K4', 'S7', 'S1', 10, 30, 5]], 0, 2], [['K4', 'S1', 600], ['K3', 'S3', 0]]], ['generated mix 52', [[['K1', 'S1', 'S2', 20, 10, 10], ['K1', 'S2', 'S5', 5, 10, 5]], 100, 2], []]]]
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
limit	`[['A', 'S8', 400], ['B', 'S9', 300]]`	`[['A', 'S8', 400]]`	Failed
generated mix 25	`[['K2', 'S4', 1200], ['K3', 'S1', 450]]`	`[['K2', 'S4', 1200], ['K3', 'S1', 450]]`	Passed
threshold equal kept	`[['A', 'S9', 100]]`	`[['A', 'S9', 100]]`	Passed
shared target	`[['A', 'S9', 400]]`	`[['A', 'S9', 400]]`	Passed
occupied target	`[['A', 'S9', 200]]`	`[['A', 'S9', 200]]`	Passed
negative benefit	`[]`	`[]`	Passed
generated mix 6	`[['K3', 'S3', 800]]`	`[['K3', 'S3', 800]]`	Passed
generated mix 14	`[['K4', 'S3', 450]]`	`[['K4', 'S3', 450]]`	Passed

SHA-256 / 64bb223b3a5e2cb9783f2048cf3fc96c05a87e960039a78889406df90b19f985

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(cands, move_cost, max_moves):
    occupied = {c[1] for c in cands}
    ranked = []
    for sku, frm, to, picks, tf, tt in cands:
        benefit = picks * (tf - tt)
        if benefit >= move_cost:
            ranked.append((-benefit, sku, frm, to))
    ranked.sort()
    plan = []
    moved = set()
    targets = set()
    vacated = set()
    for nb, sku, frm, to in ranked:
        if len(moved) + len(targets) >= max_moves:
            break
        if sku in moved or to in targets:
            continue
        if to in occupied and to not in vacated:
            continue
        plan.append([sku, to, -nb])
        moved.add(sku)
        targets.add(to)
        vacated.add(frm)
    return plan
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 25', [[['K1', 'S3', 'S6', 10, 10, 5], ['K3', 'S7', 'S1', 10, 50, 5], ['K2', 'S3', 'S4', 40, 50, 20]], 200, 2], [['K2', 'S4', 1200], ['K3', 'S1', 450]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 6', [[['K3', 'S1', 'S3', 20, 50, 10], ['K3', 'S4', 'S7', 40, 50, 40]], 400, 2], [['K3', 'S3', 800]]], ['generated mix 14', [[['K3', 'S7', 'S4', 10, 10, 30], ['K4', 'S6', 'S3', 10, 50, 5], ['K2', 'S5', 'S6', 5, 30, 10]], 200, 3], [['K4', 'S3', 450]]]], [['generated mix 62', [[['K4', 'S4', 'S5', 10, 50, 5], ['K1', 'S3', 'S4', 40, 10, 20], ['K1', 'S5', 'S2', 20, 50, 30], ['K1', 'S7', 'S6', 10, 50, 20], ['K4', 'S3', 'S5', 40, 30, 40], ['K3', 'S4', 'S6', 20, 50, 10]], 200, 1], [['K3', 'S6', 800]]], ['generated mix 59', [[['K1', 'S3', 'S7', 40, 10, 30], ['K1', 'S2', 'S5', 40, 20, 20], ['K4', 'S2', 'S3', 10, 20, 10], ['K4', 'S3', 'S2', 10, 20, 40], ['K4', 'S5', 'S1', 40, 50, 30]], 0, 2], [['K4', 'S1', 800], ['K1', 'S5', 0]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 9', [[['K1', 'S6', 'S1', 20, 20, 20], ['K3', 'S5', 'S6', 40, 20, 20]], 0, 3], [['K1', 'S1', 0], ['K3', 'S6', 0]]], ['generated mix 17', [[['K1', 'S2', 'S6', 5, 20, 20], ['K2', 'S7', 'S1', 10, 50, 30]], 50, 3], [['K2', 'S1', 200]]]], [['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]], ['generated mix 42', [[['K3', 'S7', 'S2', 10, 20, 40], ['K1', 'S6', 'S2', 10, 20, 20], ['K2', 'S5', 'S2', 20, 30, 20], ['K4', 'S7', 'S4', 40, 50, 30]], 200, 2], [['K4', 'S4', 800], ['K2', 'S2', 200]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['generated mix 20', [[['K1', 'S3', 'S7', 5, 50, 40], ['K3', 'S4', 'S5', 20, 10, 10], ['K2', 'S6', 'S5', 5, 30, 30], ['K3', 'S2', 'S5', 40, 50, 20], ['K4', 'S5', 'S7', 10, 10, 30], ['K2', 'S5', 'S4', 40, 30, 5]], 0, 1], [['K1', 'S7', 50]]], ['generated mix 28', [[['K3', 'S4', 'S2', 10, 50, 30], ['K2', 'S1', 'S3', 10, 50, 30], ['K4', 'S1', 'S2', 20, 50, 5]], 400, 2], [['K4', 'S2', 900]]]], [['generated mix 30', [[['K2', 'S4', 'S5', 5, 30, 5], ['K4', 'S3', 'S1', 40, 50, 20], ['K2', 'S6', 'S1', 5, 20, 40]], 0, 1], [['K4', 'S1', 1200]]], ['generated mix 33', [[['K3', 'S5', 'S3', 40, 50, 5], ['K2', 'S4', 'S6', 10, 20, 10], ['K4', 'S5', 'S2', 5, 50, 5], ['K4', 'S6', 'S3', 5, 20, 40], ['K4', 'S4', 'S6', 40, 30, 30]], 200, 2], [['K3', 'S3', 1800], ['K4', 'S2', 225]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 32', [[['K2', 'S5', 'S1', 10, 30, 5], ['K2', 'S1', 'S3', 5, 10, 40], ['K3', 'S5', 'S4', 20, 10, 10], ['K4', 'S3', 'S5', 10, 50, 40], ['K2', 'S4', 'S6', 40, 10, 40]], 0, 3], []], ['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]]], [['generated mix 4', [[['K3', 'S4', 'S3', 10, 50, 10], ['K4', 'S4', 'S3', 20, 20, 20], ['K3', 'S4', 'S6', 40, 20, 20], ['K4', 'S7', 'S3', 20, 20, 20], ['K4', 'S1', 'S6', 20, 50, 20]], 0, 1], [['K4', 'S6', 600]]], ['generated mix 13', [[['K2', 'S2', 'S1', 10, 10, 5], ['K4', 'S5', 'S6', 40, 20, 40], ['K2', 'S4', 'S2', 40, 30, 40], ['K3', 'S2', 'S6', 40, 50, 10]], 50, 2], [['K3', 'S6', 1600], ['K2', 'S1', 50]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['generated mix 44', [[['K3', 'S5', 'S2', 40, 20, 30], ['K3', 'S6', 'S2', 5, 50, 5], ['K3', 'S2', 'S3', 10, 20, 20], ['K4', 'S3', 'S1', 20, 50, 20], ['K4', 'S7', 'S1', 10, 30, 5]], 0, 2], [['K4', 'S1', 600], ['K3', 'S3', 0]]], ['generated mix 52', [[['K1', 'S1', 'S2', 20, 10, 10], ['K1', 'S2', 'S5', 5, 10, 5]], 100, 2], []]]]
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
limit	`[['A', 'S8', 400]]`	`[['A', 'S8', 400]]`	Passed
generated mix 25	`[['K2', 'S4', 1200]]`	`[['K2', 'S4', 1200], ['K3', 'S1', 450]]`	Failed
threshold equal kept	`[['A', 'S9', 100]]`	`[['A', 'S9', 100]]`	Passed
shared target	`[['A', 'S9', 400]]`	`[['A', 'S9', 400]]`	Passed
occupied target	`[['A', 'S9', 200]]`	`[['A', 'S9', 200]]`	Passed
negative benefit	`[]`	`[]`	Passed
generated mix 6	`[['K3', 'S3', 800]]`	`[['K3', 'S3', 800]]`	Passed
generated mix 14	`[['K4', 'S3', 450]]`	`[['K4', 'S3', 450]]`	Passed

SHA-256 / 954e45e9012357a2a122916641935d9b0fd0ac67ee9f0b9cff5b25bcd55d853e

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(cands, move_cost, max_moves):
    occupied = {c[1] for c in cands}
    ranked = []
    for sku, frm, to, picks, tf, tt in cands:
        benefit = picks * (tf - tt)
        if benefit >= move_cost:
            ranked.append((-benefit, sku, frm, to))
    ranked.sort()
    plan = []
    moved = set()
    targets = set()
    vacated = set()
    for nb, sku, frm, to in ranked:
        if len(plan) >= max_moves:
            break
        if sku in moved or to in targets:
            continue
        if to in occupied and to not in vacated:
            continue
        plan.append([sku, to, -nb])
        moved.add(sku)
        targets.add(to)
        vacated.add(frm)
    return plan
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 25', [[['K1', 'S3', 'S6', 10, 10, 5], ['K3', 'S7', 'S1', 10, 50, 5], ['K2', 'S3', 'S4', 40, 50, 20]], 200, 2], [['K2', 'S4', 1200], ['K3', 'S1', 450]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 6', [[['K3', 'S1', 'S3', 20, 50, 10], ['K3', 'S4', 'S7', 40, 50, 40]], 400, 2], [['K3', 'S3', 800]]], ['generated mix 14', [[['K3', 'S7', 'S4', 10, 10, 30], ['K4', 'S6', 'S3', 10, 50, 5], ['K2', 'S5', 'S6', 5, 30, 10]], 200, 3], [['K4', 'S3', 450]]]], [['generated mix 62', [[['K4', 'S4', 'S5', 10, 50, 5], ['K1', 'S3', 'S4', 40, 10, 20], ['K1', 'S5', 'S2', 20, 50, 30], ['K1', 'S7', 'S6', 10, 50, 20], ['K4', 'S3', 'S5', 40, 30, 40], ['K3', 'S4', 'S6', 20, 50, 10]], 200, 1], [['K3', 'S6', 800]]], ['generated mix 59', [[['K1', 'S3', 'S7', 40, 10, 30], ['K1', 'S2', 'S5', 40, 20, 20], ['K4', 'S2', 'S3', 10, 20, 10], ['K4', 'S3', 'S2', 10, 20, 40], ['K4', 'S5', 'S1', 40, 50, 30]], 0, 2], [['K4', 'S1', 800], ['K1', 'S5', 0]]], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['generated mix 9', [[['K1', 'S6', 'S1', 20, 20, 20], ['K3', 'S5', 'S6', 40, 20, 20]], 0, 3], [['K1', 'S1', 0], ['K3', 'S6', 0]]], ['generated mix 17', [[['K1', 'S2', 'S6', 5, 20, 20], ['K2', 'S7', 'S1', 10, 50, 30]], 50, 3], [['K2', 'S1', 200]]]], [['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]], ['generated mix 42', [[['K3', 'S7', 'S2', 10, 20, 40], ['K1', 'S6', 'S2', 10, 20, 20], ['K2', 'S5', 'S2', 20, 30, 20], ['K4', 'S7', 'S4', 40, 50, 30]], 200, 2], [['K4', 'S4', 800], ['K2', 'S2', 200]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['shared target', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 5], [['A', 'S9', 400]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['generated mix 20', [[['K1', 'S3', 'S7', 5, 50, 40], ['K3', 'S4', 'S5', 20, 10, 10], ['K2', 'S6', 'S5', 5, 30, 30], ['K3', 'S2', 'S5', 40, 50, 20], ['K4', 'S5', 'S7', 10, 10, 30], ['K2', 'S5', 'S4', 40, 30, 5]], 0, 1], [['K1', 'S7', 50]]], ['generated mix 28', [[['K3', 'S4', 'S2', 10, 50, 30], ['K2', 'S1', 'S3', 10, 50, 30], ['K4', 'S1', 'S2', 20, 50, 5]], 400, 2], [['K4', 'S2', 900]]]], [['generated mix 30', [[['K2', 'S4', 'S5', 5, 30, 5], ['K4', 'S3', 'S1', 40, 50, 20], ['K2', 'S6', 'S1', 5, 20, 40]], 0, 1], [['K4', 'S1', 1200]]], ['generated mix 33', [[['K3', 'S5', 'S3', 40, 50, 5], ['K2', 'S4', 'S6', 10, 20, 10], ['K4', 'S5', 'S2', 5, 50, 5], ['K4', 'S6', 'S3', 5, 20, 40], ['K4', 'S4', 'S6', 40, 30, 30]], 200, 2], [['K3', 'S3', 1800], ['K4', 'S2', 225]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['sku once', [[['A', 'S1', 'S8', 10, 50, 10], ['A', 'S1', 'S9', 10, 50, 20]], 0, 5], [['A', 'S8', 400]]], ['negative benefit', [[['A', 'S1', 'S9', 10, 20, 30]], 0, 5], []], ['generated mix 32', [[['K2', 'S5', 'S1', 10, 30, 5], ['K2', 'S1', 'S3', 5, 10, 40], ['K3', 'S5', 'S4', 20, 10, 10], ['K4', 'S3', 'S5', 10, 50, 40], ['K2', 'S4', 'S6', 40, 10, 40]], 0, 3], []], ['generated mix 41', [[['K2', 'S6', 'S1', 40, 30, 40], ['K1', 'S2', 'S4', 10, 30, 5], ['K2', 'S4', 'S6', 5, 30, 10], ['K2', 'S4', 'S7', 40, 30, 5], ['K3', 'S3', 'S5', 5, 20, 5], ['K1', 'S4', 'S6', 5, 20, 30]], 50, 1], [['K2', 'S7', 1000]]]], [['generated mix 4', [[['K3', 'S4', 'S3', 10, 50, 10], ['K4', 'S4', 'S3', 20, 20, 20], ['K3', 'S4', 'S6', 40, 20, 20], ['K4', 'S7', 'S3', 20, 20, 20], ['K4', 'S1', 'S6', 20, 50, 20]], 0, 1], [['K4', 'S6', 600]]], ['generated mix 13', [[['K2', 'S2', 'S1', 10, 10, 5], ['K4', 'S5', 'S6', 40, 20, 40], ['K2', 'S4', 'S2', 40, 30, 40], ['K3', 'S2', 'S6', 40, 50, 10]], 50, 2], [['K3', 'S6', 1600], ['K2', 'S1', 50]]], ['occupied target', [[['A', 'S1', 'S9', 10, 30, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 200]]], ['threshold equal kept', [[['A', 'S1', 'S9', 10, 30, 20]], 100, 5], [['A', 'S9', 100]]], ['limit', [[['A', 'S1', 'S8', 10, 50, 10], ['B', 'S2', 'S9', 10, 40, 10]], 0, 1], [['A', 'S8', 400]]], ['chain into vacated', [[['A', 'S1', 'S9', 10, 50, 10], ['B', 'S2', 'S1', 10, 40, 10]], 0, 5], [['A', 'S9', 400], ['B', 'S1', 300]]], ['generated mix 44', [[['K3', 'S5', 'S2', 40, 20, 30], ['K3', 'S6', 'S2', 5, 50, 5], ['K3', 'S2', 'S3', 10, 20, 20], ['K4', 'S3', 'S1', 20, 50, 20], ['K4', 'S7', 'S1', 10, 30, 5]], 0, 2], [['K4', 'S1', 600], ['K3', 'S3', 0]]], ['generated mix 52', [[['K1', 'S1', 'S2', 20, 10, 10], ['K1', 'S2', 'S5', 5, 10, 5]], 100, 2], []]]]
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
limit	`[['A', 'S8', 400]]`	`[['A', 'S8', 400]]`	Passed
generated mix 25	`[['K2', 'S4', 1200], ['K3', 'S1', 450]]`	`[['K2', 'S4', 1200], ['K3', 'S1', 450]]`	Passed
threshold equal kept	`[['A', 'S9', 100]]`	`[['A', 'S9', 100]]`	Passed
shared target	`[['A', 'S9', 400]]`	`[['A', 'S9', 400]]`	Passed
occupied target	`[['A', 'S9', 200]]`	`[['A', 'S9', 200]]`	Passed
negative benefit	`[]`	`[]`	Passed
generated mix 6	`[['K3', 'S3', 800]]`	`[['K3', 'S3', 800]]`	Passed
generated mix 14	`[['K4', 'S3', 450]]`	`[['K4', 'S3', 450]]`	Passed

SHA-256 / ecebc25df2c69b04848fe0491703084c6f94b0a4194d629f3b32894bccd1f21f

Verification & scope

Greedy stipulated planner; no swap sequencing or labour scheduling. 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 2026-09-29T14:52:10.907604+00:00.

Case digest / 26e7d0d17af89777e47d8396a5a6b84933ca97e64083a9f9aff6d46b56ae9b97