FA-93321 / EV charging session scheduling / Open access

Site power profile from charge plans: segment coverage · case 01

The final segment of every charging interval drops out of the site profile.

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

ROOT CAUSE

The coverage test requires the segment to end strictly before the interval end.

VERIFIED REPAIR

An interval covers segment [a, b) when s <= a and b <= e.

Unsuccessful approach: Requiring s < a drops the first segment instead.

Case contract

plan holds [start, end, kw] charging intervals ([start, end), zero-length ignored). Build the site profile as change points [[t, total_kw]] over the interval breakpoints, merging equal consecutive levels, and close with [last breakpoint, 0] unless the profile already ends at 0. Also return the start points of segments whose total exceeds site_max. Return [profile, overloads].

Why this case matters

Depot, workplace and public EV chargers schedule sessions against prices, circuit limits and departure deadlines; a wrong decision silently strands a driver or overloads a feeder.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(plan, site_max):
    pts = sorted({t for s, e, _ in plan for t in (s, e) if e > s})
    out = []
    over = []
    for a, b in zip(pts, pts[1:]):
        kw = sum(k for s, e, k in plan if s <= a and b < e)
        if out and out[-1][1] == kw:
            continue
        out.append([a, kw])
        if kw > site_max:
            over.append(a)
    if pts:
        if not out or out[-1][1] != 0:
            out.append([pts[-1], 0])
    return [out, over]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[23, 28, 11], [8, 13, 0], [15, 20, 0], [24, 24, 4], [16, 16, 0]], 15],
   [[[8, 0], [23, 11], [28, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[4, 14, 11], [0, 2, 0], [16, 18, 0]], 11],
   [[[0, 0], [4, 11], [14, 0]], []]],
  ['control 1', [[[23, 38, 0], [0, 5, 4], [18, 18, 11]], 15], [[[0, 4], [5, 0]], []]],
  ['control 2', [[[6, 8, 7]], 22], [[[6, 7], [8, 0]], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[11, 13, 4], [13, 28, 0], [17, 22, 0], [9, 11, 4]], 22],
   [[[9, 4], [13, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[11, 16, 0], [11, 16, 7], [19, 21, 11], [8, 18, 11], [16, 16, 0]], 15],
   [[[8, 11], [11, 18], [16, 11], [18, 0], [19, 11], [21, 0]], [11]]],
  ['control 1', [[[12, 12, 4], [7, 12, 11], [27, 37, 4]], 22],
   [[[7, 11], [12, 0], [27, 4], [37, 0]], []]],
  ['control 2', [[], 18], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[2, 17, 7]], 11], [[[2, 7], [17, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[9, 14, 0], [6, 8, 7]], 7],
   [[[6, 7], [8, 0]], []]],
  ['control 1', [[[21, 31, 11], [23, 33, 7], [0, 10, 7], [25, 25, 0], [28, 43, 7]], 15],
   [[[0, 7], [10, 0], [21, 11], [23, 18], [28, 25], [31, 14], [33, 7], [43, 0]], [23, 28]]],
  ['control 2', [[[17, 27, 11], [22, 37, 11], [10, 10, 7], [19, 29, 11]], 7],
   [[[17, 11], [19, 22], [22, 33], [27, 22], [29, 11], [37, 0]], [17, 19, 22, 27, 29]]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[10, 12, 7], [3, 8, 0], [29, 39, 11], [6, 11, 7], [13, 23, 7]], 11],
   [[[3, 0], [6, 7], [10, 14], [11, 7], [12, 0], [13, 7], [23, 0], [29, 11], [39, 0]], [10]]],
  ['regression: segment coverage (partial repair)', [[[19, 21, 11], [15, 30, 7], [30, 45, 11]], 22],
   [[[15, 7], [19, 18], [21, 7], [30, 11], [45, 0]], []]],
  ['control 1', [[], 22], [[], []]], ['control 2', [[], 22], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[15, 25, 11], [27, 27, 0], [26, 26, 11]], 22],
   [[[15, 11], [25, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[26, 36, 11], [11, 26, 11], [19, 24, 11], [13, 23, 11], [0, 0, 4]], 18],
   [[[11, 11], [13, 22], [19, 33], [23, 22], [24, 11], [36, 0]], [13, 19, 23]]],
  ['control 1', [[[8, 8, 11], [0, 0, 11], [7, 17, 7]], 7], [[[7, 7], [17, 0]], []]],
  ['control 2', [[[22, 22, 11], [5, 5, 4], [10, 15, 11], [22, 32, 11], [14, 14, 0]], 11],
   [[[10, 11], [15, 0], [22, 11], [32, 0]], []]]]]
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
boundary: zero-length interval before plan	`[[[10, 0]], []]`	`[[[10, 11], [20, 0]], []]`	Failed
boundary: exact site limit	`[[[0, 0]], []]`	`[[[0, 11], [10, 0]], []]`	Failed
boundary: empty plan	`[[], []]`	`[[], []]`	Passed
regression: segment coverage	`[[[8, 0]], []]`	`[[[8, 0], [23, 11], [28, 0]], []]`	Failed
regression: segment coverage (partial repair)	`[[[0, 0]], []]`	`[[[0, 0], [4, 11], [14, 0]], []]`	Failed
control 1	`[[[0, 0]], []]`	`[[[0, 4], [5, 0]], []]`	Failed
control 2	`[[[6, 0]], []]`	`[[[6, 7], [8, 0]], []]`	Failed

SHA-256 / f84ff99a37d94a994202cb5d06bf462cdb42c194c148ffaaa4ca3f376a15f2bc

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(plan, site_max):
    pts = sorted({t for s, e, _ in plan for t in (s, e) if e > s})
    out = []
    over = []
    for a, b in zip(pts, pts[1:]):
        kw = sum(k for s, e, k in plan if s < a and b <= e)
        if out and out[-1][1] == kw:
            continue
        out.append([a, kw])
        if kw > site_max:
            over.append(a)
    if pts:
        if not out or out[-1][1] != 0:
            out.append([pts[-1], 0])
    return [out, over]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[23, 28, 11], [8, 13, 0], [15, 20, 0], [24, 24, 4], [16, 16, 0]], 15],
   [[[8, 0], [23, 11], [28, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[4, 14, 11], [0, 2, 0], [16, 18, 0]], 11],
   [[[0, 0], [4, 11], [14, 0]], []]],
  ['control 1', [[[23, 38, 0], [0, 5, 4], [18, 18, 11]], 15], [[[0, 4], [5, 0]], []]],
  ['control 2', [[[6, 8, 7]], 22], [[[6, 7], [8, 0]], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[11, 13, 4], [13, 28, 0], [17, 22, 0], [9, 11, 4]], 22],
   [[[9, 4], [13, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[11, 16, 0], [11, 16, 7], [19, 21, 11], [8, 18, 11], [16, 16, 0]], 15],
   [[[8, 11], [11, 18], [16, 11], [18, 0], [19, 11], [21, 0]], [11]]],
  ['control 1', [[[12, 12, 4], [7, 12, 11], [27, 37, 4]], 22],
   [[[7, 11], [12, 0], [27, 4], [37, 0]], []]],
  ['control 2', [[], 18], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[2, 17, 7]], 11], [[[2, 7], [17, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[9, 14, 0], [6, 8, 7]], 7],
   [[[6, 7], [8, 0]], []]],
  ['control 1', [[[21, 31, 11], [23, 33, 7], [0, 10, 7], [25, 25, 0], [28, 43, 7]], 15],
   [[[0, 7], [10, 0], [21, 11], [23, 18], [28, 25], [31, 14], [33, 7], [43, 0]], [23, 28]]],
  ['control 2', [[[17, 27, 11], [22, 37, 11], [10, 10, 7], [19, 29, 11]], 7],
   [[[17, 11], [19, 22], [22, 33], [27, 22], [29, 11], [37, 0]], [17, 19, 22, 27, 29]]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[10, 12, 7], [3, 8, 0], [29, 39, 11], [6, 11, 7], [13, 23, 7]], 11],
   [[[3, 0], [6, 7], [10, 14], [11, 7], [12, 0], [13, 7], [23, 0], [29, 11], [39, 0]], [10]]],
  ['regression: segment coverage (partial repair)', [[[19, 21, 11], [15, 30, 7], [30, 45, 11]], 22],
   [[[15, 7], [19, 18], [21, 7], [30, 11], [45, 0]], []]],
  ['control 1', [[], 22], [[], []]], ['control 2', [[], 22], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[15, 25, 11], [27, 27, 0], [26, 26, 11]], 22],
   [[[15, 11], [25, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[26, 36, 11], [11, 26, 11], [19, 24, 11], [13, 23, 11], [0, 0, 4]], 18],
   [[[11, 11], [13, 22], [19, 33], [23, 22], [24, 11], [36, 0]], [13, 19, 23]]],
  ['control 1', [[[8, 8, 11], [0, 0, 11], [7, 17, 7]], 7], [[[7, 7], [17, 0]], []]],
  ['control 2', [[[22, 22, 11], [5, 5, 4], [10, 15, 11], [22, 32, 11], [14, 14, 0]], 11],
   [[[10, 11], [15, 0], [22, 11], [32, 0]], []]]]]
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
boundary: zero-length interval before plan	`[[[10, 0]], []]`	`[[[10, 11], [20, 0]], []]`	Failed
boundary: exact site limit	`[[[0, 0]], []]`	`[[[0, 11], [10, 0]], []]`	Failed
boundary: empty plan	`[[], []]`	`[[], []]`	Passed
regression: segment coverage	`[[[8, 0]], []]`	`[[[8, 0], [23, 11], [28, 0]], []]`	Failed
regression: segment coverage (partial repair)	`[[[0, 0]], []]`	`[[[0, 0], [4, 11], [14, 0]], []]`	Failed
control 1	`[[[0, 0]], []]`	`[[[0, 4], [5, 0]], []]`	Failed
control 2	`[[[6, 0]], []]`	`[[[6, 7], [8, 0]], []]`	Failed

SHA-256 / f98c77be2cceccf1547911cbe7e3f3207feb8df9fea36edd8c06aa297cfb8eef

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(plan, site_max):
    pts = sorted({t for s, e, _ in plan for t in (s, e) if e > s})
    out = []
    over = []
    for a, b in zip(pts, pts[1:]):
        kw = sum(k for s, e, k in plan if s <= a and b <= e)
        if out and out[-1][1] == kw:
            continue
        out.append([a, kw])
        if kw > site_max:
            over.append(a)
    if pts:
        if not out or out[-1][1] != 0:
            out.append([pts[-1], 0])
    return [out, over]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[23, 28, 11], [8, 13, 0], [15, 20, 0], [24, 24, 4], [16, 16, 0]], 15],
   [[[8, 0], [23, 11], [28, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[4, 14, 11], [0, 2, 0], [16, 18, 0]], 11],
   [[[0, 0], [4, 11], [14, 0]], []]],
  ['control 1', [[[23, 38, 0], [0, 5, 4], [18, 18, 11]], 15], [[[0, 4], [5, 0]], []]],
  ['control 2', [[[6, 8, 7]], 22], [[[6, 7], [8, 0]], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[11, 13, 4], [13, 28, 0], [17, 22, 0], [9, 11, 4]], 22],
   [[[9, 4], [13, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[11, 16, 0], [11, 16, 7], [19, 21, 11], [8, 18, 11], [16, 16, 0]], 15],
   [[[8, 11], [11, 18], [16, 11], [18, 0], [19, 11], [21, 0]], [11]]],
  ['control 1', [[[12, 12, 4], [7, 12, 11], [27, 37, 4]], 22],
   [[[7, 11], [12, 0], [27, 4], [37, 0]], []]],
  ['control 2', [[], 18], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[2, 17, 7]], 11], [[[2, 7], [17, 0]], []]],
  ['regression: segment coverage (partial repair)', [[[9, 14, 0], [6, 8, 7]], 7],
   [[[6, 7], [8, 0]], []]],
  ['control 1', [[[21, 31, 11], [23, 33, 7], [0, 10, 7], [25, 25, 0], [28, 43, 7]], 15],
   [[[0, 7], [10, 0], [21, 11], [23, 18], [28, 25], [31, 14], [33, 7], [43, 0]], [23, 28]]],
  ['control 2', [[[17, 27, 11], [22, 37, 11], [10, 10, 7], [19, 29, 11]], 7],
   [[[17, 11], [19, 22], [22, 33], [27, 22], [29, 11], [37, 0]], [17, 19, 22, 27, 29]]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage',
   [[[10, 12, 7], [3, 8, 0], [29, 39, 11], [6, 11, 7], [13, 23, 7]], 11],
   [[[3, 0], [6, 7], [10, 14], [11, 7], [12, 0], [13, 7], [23, 0], [29, 11], [39, 0]], [10]]],
  ['regression: segment coverage (partial repair)', [[[19, 21, 11], [15, 30, 7], [30, 45, 11]], 22],
   [[[15, 7], [19, 18], [21, 7], [30, 11], [45, 0]], []]],
  ['control 1', [[], 22], [[], []]], ['control 2', [[], 22], [[], []]]],
 [['boundary: zero-length interval before plan', [[[5, 5, 7], [10, 20, 11]], 11],
   [[[10, 11], [20, 0]], []]],
  ['boundary: exact site limit', [[[0, 10, 7], [0, 10, 4]], 11], [[[0, 11], [10, 0]], []]],
  ['boundary: empty plan', [[], 11], [[], []]],
  ['regression: segment coverage', [[[15, 25, 11], [27, 27, 0], [26, 26, 11]], 22],
   [[[15, 11], [25, 0]], []]],
  ['regression: segment coverage (partial repair)',
   [[[26, 36, 11], [11, 26, 11], [19, 24, 11], [13, 23, 11], [0, 0, 4]], 18],
   [[[11, 11], [13, 22], [19, 33], [23, 22], [24, 11], [36, 0]], [13, 19, 23]]],
  ['control 1', [[[8, 8, 11], [0, 0, 11], [7, 17, 7]], 7], [[[7, 7], [17, 0]], []]],
  ['control 2', [[[22, 22, 11], [5, 5, 4], [10, 15, 11], [22, 32, 11], [14, 14, 0]], 11],
   [[[10, 11], [15, 0], [22, 11], [32, 0]], []]]]]
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
boundary: zero-length interval before plan	`[[[10, 11], [20, 0]], []]`	`[[[10, 11], [20, 0]], []]`	Passed
boundary: exact site limit	`[[[0, 11], [10, 0]], []]`	`[[[0, 11], [10, 0]], []]`	Passed
boundary: empty plan	`[[], []]`	`[[], []]`	Passed
regression: segment coverage	`[[[8, 0], [23, 11], [28, 0]], []]`	`[[[8, 0], [23, 11], [28, 0]], []]`	Passed
regression: segment coverage (partial repair)	`[[[0, 0], [4, 11], [14, 0]], []]`	`[[[0, 0], [4, 11], [14, 0]], []]`	Passed
control 1	`[[[0, 4], [5, 0]], []]`	`[[[0, 4], [5, 0]], []]`	Passed
control 2	`[[[6, 7], [8, 0]], []]`	`[[[6, 7], [8, 0]], []]`	Passed

SHA-256 / 8c02e729e67a3aca477ac960c3566c4c528103267868f6e0aecd84b0d7f130e3

Verification & scope

Deterministic stipulated toy contract for teaching; no claim of conformance with any standard, vendor protocol or production controller. 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 2026-09-29T14:51:54.232043+00:00.

Case digest / 9b351213aaaf795cde6aac4c60c8187a00107cc6c4e59a55828499fe1568bf47