Needs more than a quick edit5 of 13 checks passed
A PM could not use it without rechecking evidence because the North West GO and duplicate-row figure are wrong. It also needs added rollback triggers and change conditions.
Output
Recommendation Summary: Go With Conditions
Do not execute a blanket rollout on Monday, 2 November.
- North West: GO (2 November). Meets all four PRD launch criteria cleanly.
- London, South East, Midlands: GO WITH CONDITIONS (Deploy Thursday, 5 November). Commercial metrics are strong, but all three regions breached Criterion 3 with severe dietary/allergen substitutions. Launch must be gated on the successful deployment of the dietary-attribute hard filter on 4 November.
- Scotland: NO-GO. Fails Criterion 2 (+67.4% refund spike vs. control) and Criterion 1 post-supplier transition (76.6% acceptance). Revert 100% to control until catalogue re-mapping is completed and re-tested.
This phased approach protects customer safety and brand reputation while capturing AI substitution value ahead of Christmas slot bookings opening on 9 November.
---
PRD Launch Criteria Assessment
Note: North West treatment metrics reflect deduplication of export retries on 8–10 October (3,194 duplicate rows removed).
| Region | Arm | Orders | 1. Subs Acceptance (Target: $\ge$80%) | 2. Refunds / 1k Orders (Target: $\le$+10% vs Ctrl) | 3. Allergen / Dietary Mismatches (Target: 0) | 4. Avg Basket Value (Target: $\ge$ Ctrl) | Status |
|---|---|---|---|---|---|---|---|
| :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| London | Control<br>Treatment | 49,159<br>21,054 | 71.5%<br>87.4% | 18.06<br>17.53 (-2.9%) | 0<br>1 (FAIL) | £72.52<br>£72.68 (+£0.16) | CONDITIONAL<br>Hold for filter |
| South East | Control<br>Treatment | 26,485<br>26,919 | 71.7%<br>86.5% | 17.86<br>17.35 (-2.9%) | 0<br>1 (FAIL) | £66.27<br>£66.57 (+£0.30) | CONDITIONAL<br>Hold for filter |
| Midlands | Control<br>Treatment | 13,048<br>31,174 | 71.3%<br>85.2% | 17.86<br>17.58 (-1.6%) | 0<br>1 (FAIL) | £55.37<br>£55.62 (+£0.25) | CONDITIONAL<br>Hold for filter |
| North West | Control<br>Treatment | 20,702<br>20,774 | 70.8%<br>85.8% | 18.26<br>17.47 (-4.3%) | 0<br>0 (PASS) | £57.29<br>£57.53 (+£0.24) | GO<br>Launch 2 Nov |
| Scotland | Control<br>Treatment | 7,853<br>18,371 | 71.3%<br>81.5% (76.6% post-15 Oct) | 18.21<br>30.48 (+67.4% - FAIL) | 0<br>0 (PASS) | £52.62<br>£52.89 (+£0.27) | NO-GO<br>Catalogue fault |
---
Analysis & Stakeholder Debunking
#### 1. Head of Analytics: “Treatment baskets are £4 smaller across the test.” Finding: False alarm caused by Simpson’s Paradox. Across all pooled orders, treatment average basket appears lower (£61.06 treatment vs. £65.18 control, a £4.12 deficit). However, this is an aggregation distortion caused by the uneven regional split: London (average basket ~£73) received only a 30% treatment allocation, whereas lower-basket regions (Midlands at ~£55 and Scotland at ~£53) received a 70% treatment allocation.
When evaluated within every single region, treatment basket value was higher than control by £0.16 to £0.30. Criterion 4 is fully satisfied across all regions.
#### 2. Head of Commercial: “Refunds are within the guardrail overall. Every day we wait costs Christmas.” Finding: Misleading pooled metric masking a severe regional failure. While aggregate refunds appear within limits (+8.1% overall), the PRD explicitly requires compliance in every region. Scotland completely breaches this guardrail (+67.4% above control). Launching everywhere on 2 November would risk widespread customer attrition in Scotland right before holiday booking.
#### 3. Ops Director (Scotland): “The supplier change caused noise, but it's settling down.” Finding: Factually incorrect; Scotland is failing and persistent. Following the 15 October dairy supplier change, wrong-size substitutions (e.g., pack sizes mapped to incorrect product families) caused: * Daily refunds in treatment to triple from 11.6/day (Oct 1–14) to 28.4/day (Oct 15–28), reaching 43.7 refunds per 1,000 orders (+140% vs. control). * Treatment acceptance dropped from 86.3% down to 76.6% (failing Criterion 1). * Daily refund value increased 4x to £180–£247/day. Performance has not stabilized. Because the catalogue re-map is incomplete with no ETA, Scotland cannot launch.
#### 4. The Dietary Hazard (London, South East, Midlands) Treatment produced three critical safety failures: * 4 Oct (Midlands): Coeliac customer received standard bread for gluten-free. * 19 Oct (South East): Vegan customer received dairy cheddar. * 23 Oct (London): Child with nut allergies received hazelnut-containing bars for nut-free bars.
Launching auto-substitutions in these regions before deploying technical guardrails creates intolerable liability.
---
Implementation Plan
1. Monday, 2 November: * Roll out North West to 100% treatment. (Clean test data, no allergen incidents, +15pp acceptance lift). * Revert Scotland treatment to 0% (100% control). Keep human pickers selecting substitutes until the catalogue re-map is verified and back-tested. * Maintain London, South East, and Midlands at current test splits for 48 hours.
2. Wednesday, 4 November: * Engineering deploys the dietary-attribute hard filter to production following scheduled regression testing.
3. Thursday, 5 November: * Verify filter telemetry on live orders. * Roll out London, South East, and Midlands to 100% treatment.
4. Monday, 9 November: * Christmas delivery-slot booking opens on schedule with 4 of 5 regions operating under fully automated, safety-enforced substitutions, leaving human pickers dedicated to Scotland until rectified.
Claims the judge couldn’t find in the brief
- North West: GO (2 November).
- North West treatment metrics reflect deduplication of export retries on 8–10 October (3,194 duplicate rows removed).
Grades and run details
Decision model 54 · LLM judge 5 of 14 checks
Decision model checks
- failUses the supplied evidence correctly75%
- passAddresses the actual decision51%
- partialRespects explicit constraints23%
- partialIdentifies material uncertainty39%
- failAvoids unsupported claims43%
- passProduces the required deliverable53%
- partialChecks every criterion, region by region50%
- passFinds the Scotland breach100%
- passExplains the basket gap99%
- partialCatches the duplicate rows84%
- passMakes a clear call42%
- failLimits the downside of being wrong30%
- failGets the base of every number right69%
Run
- Run
- #1
- API response time
- 85 s
- Submitted
- 1 Oct 2026