Overview

An analysis of 147 Pentana DMS records was conducted to determine the most reliable insurance renewal month for each vehicle. The key findings are:

1. The Matched flag confirms insurance-verified renewal months for 59 of 147 records. When Matched = true, the RenewalMonth field in Pentana is confirmed correct by the insurance company's database.
2. month(RegDate) is the correct renewal proxy — it agrees with the insurer-confirmed renewal month in 100% of Matched=true records, and in 94% of Matched=false records where a clean registration date exists.
3. All 88 unmatched records have been assigned an alternate renewal month (AltRenewalMonth) using month(DeliveryDate) as the anchor. This is warranted because when delivery and registration fall in different calendar months, the insurance policy is written at the point of vehicle handover (delivery), not at registration.
4. A corrected DeliveryMonth field was identified and resolved: 12 records in the source data had DeliveryMonth set to month(RegDate) rather than month(DeliveryDate). These are corrected in pentana_matched_clean.

1. What the Matched Column Means

The Matched field was matched against an automotive insurance company's policy database using VIN and/or registration number.

2. Core Pattern — What Makes a Record Match

Analysis of the relationship between DeliveryDate and RegDate for all records reveals a single dominant pattern:

A record is Matched = true if and only if delivery and registration occurred in the same calendar month.

The rule holds at 100% precision for all records with a delivery-to-registration lag of 0–31 days:

The four Matched = true records that appear to cross calendar months are all vehicles where the original DeliveryMonth field in Pentana was corrupt — it stored month(RegDate) rather than month(DeliveryDate). These are corrected in pentana_matched_clean.

3. Renewal Month Proxy Accuracy

Using the 95 records with a clean registration date (year ≥ 2015, RegDate not null):

month(RegDate) is by far the strongest proxy — it fails on only 2 records (YGL68Z and K63DD), both of which have an unexplained +2 month offset in the Pentana system (possibly a configurable grace period or DMS anomaly — requires confirmation with Pentana).

month(DeliveryDate) scores 57.9% because it fails on all 40 records where delivery and registration fall in different months. However, for those same cross-month records, month(DeliveryDate) is what the insurer uses — making it the correct alternate for unmatched records.

4. Rules for Assigning the Best-Estimate Renewal Month

All logic is implemented in the pentana_renewal_corrected table with three new columns:

Rule hierarchy — first matching rule wins

5. Revised Renewal Month Distribution

Using AltRenewalMonth across all 147 records:

6. Data Quality Issues Requiring Remediation

7. Rules Summary — Decision Logic

Complete rule set in priority order. First matching condition wins.

-- AltRenewalMonth assignment logic (priority order)

CASE

  -- Rule 1: Insurance-confirmed
  WHEN Matched = true
    → AltRenewalMonth = RenewalMonth                  -- confirmed

  -- Rule 2: EOM cross-month batch
  WHEN Matched = false
       AND RegDate IS NOT NULL AND year(RegDate) >= 2015
       AND lag BETWEEN -7 AND 28 days
       AND month(RegDate) != month(DeliveryDate)
    → AltRenewalMonth = month(DeliveryDate)            -- derived_eom

  -- Rule 3: Future / pending RegDate
  WHEN Matched = false
       AND RegDate IS NOT NULL AND year(RegDate) >= 2015
       AND lag < -7 days
    → AltRenewalMonth = month(DeliveryDate)            -- derived_future_regdate

  -- Rule 4: Bad RegDate (sentinel)
  WHEN Matched = false
       AND year(RegDate) < 2015
    → AltRenewalMonth = month(DeliveryDate)            -- derived_bad_regdate

  -- Rule 5: No RegDate
  WHEN Matched = false
       AND RegDate IS NULL
    → AltRenewalMonth = month(DeliveryDate)            -- derived_delivery_only

  -- Rule 6: Lag 29–90 days
  WHEN Matched = false
       AND RegDate IS NOT NULL AND year(RegDate) >= 2015
       AND lag BETWEEN 29 AND 90 days
    → AltRenewalMonth = month(DeliveryDate)            -- derived_lag_29_90d

  -- Rule 7: Long lag — used vehicle / re-registration
  WHEN Matched = false
       AND RegDate IS NOT NULL AND year(RegDate) >= 2015
       AND lag > 90 days
    → AltRenewalMonth = month(DeliveryDate)            -- derived_long_lag

END

-- Universal fallback for all unmatched cases:
-- AltRenewalMonth = month(DeliveryDate)
-- Insurance policies are written at the point of vehicle handover.

8. Recommendations

1. Use pentana_renewal_corrected.AltRenewalMonth for all campaign scheduling. Filter by AltRenewalConfidence to manage risk:
   • confirmed + derived_eom + derived_future_regdate → include with full confidence
   • derived_delivery_only + derived_long_lag + derived_lag_29_90d → include with a review flag
   • derived_bad_regdate → exclude until RegDate is resolved
2. Do not use the Matched field as a campaign audience filter. Filtering to Matched = true only removes 88 records with derivable renewal months, reducing campaign reach by 60% unnecessarily.
3. Do not use Pentana's DeliveryMonth field directly. 12 records have it set to month(RegDate) rather than month(DeliveryDate). Always derive delivery month as month(DeliveryDate).
4. Backfill RegDate for the 48 no-RegDate records via REGO/NEVDIS API. These are the only records where the alternate is a best-guess with no cross-check available.
5. Confirm RegDate semantics with Pentana: Does RegDate always reflect the current owner's registration, or can it carry a prior owner's date? Clarifying this affects how long-lag used-vehicle records are treated.
6. Investigate the +2 month offset on YGL68Z and K63DD. If this is a Pentana system configuration, it may affect a larger population in a full extract.
7. Request a full Pentana extract. At 147 records, April is over-represented due to a single new-stock wave. A full historical extract is needed for reliable seasonality modelling.