# Governance and lineage across the OEM-supplier-dealer chain
A single brake caliper leaves a Tier-1 supplier (a direct supplier to the automaker) with the part number BRBRThe percentage of visitors who leave after viewing only one page, often a signal of poor relevance, mismatched intent, or weak user experience.Voir la définition complète →-4471-A. By the time it reaches a dealer's service bay, that same physical part is called 4471A in the OEM's (Original Equipment Manufacturer, the automaker) parts catalog, 04471-AA in the warranty system, and BR4471A-EU in the European logistics feed. Four names, one part. When a recall hits, which record does the technician trust?
That gap is the whole problem this lesson solves. Governance decides who owns each field. Master data managementMaster data managementMaster Data Management (MDM) is the discipline of creating and maintaining a single, consistent, trusted version of an organization's core business entities like customers, products, and suppliers. () forces the four names into one trusted record. Lineage traces where every value came from. Stewardship KPIs keep that record honest over time.
Follow the part number across three parties and you touch every major automotive dataset:
Each party assigns its own identifier. Nobody is wrong. They just never agreed on a shared key. That is the governance vacuum where dirty data breeds.
Ownership is not "who stores the data." It is "who is accountable for a field being correct."
A useful rule: the party closest to the source of truth owns the field.
Write this down in a RACI (Responsible, Accountable, Consulted, Informed) matrix per field. When the caliper's torque spec changes, everyone knows the Tier-1 engineer is Accountable and the OEM parts team is Consulted. No committee, no email chain.
MDMMDMMaster Data Management (MDM) is the discipline of creating and maintaining a single, consistent, trusted version of an organization's core business entities like customers, products, and suppliers.Voir la définition complète → is the discipline of creating one trusted version of a shared entity. That trusted version is the golden record.
For our caliper, the golden record answers: what is the single canonical part, and what are all its known aliases?
The technical move is entity resolution: matching BRBRThe percentage of visitors who leave after viewing only one page, often a signal of poor relevance, mismatched intent, or weak user experience.Voir la définition complète →-4471-A, 4471A, 04471-AA, and BR4471A-EU to one master ID. A minimal crosswalk table:
-- Golden record crosswalk for one part
CREATE TABLE part_master (
master_part_id VARCHAR PRIMARY KEY, -- 'MP-100293'
canonical_name VARCHAR, -- 'Brake Caliper, Front Left'
fitment_vin_prefix VARCHAR -- WBA... (owned by OEM)
);
CREATE TABLE part_alias (
master_part_id VARCHAR REFERENCES part_master,
source_system VARCHAR, -- 'TIER1_ERP', 'OEM_CATALOG', 'WARRANTY', 'EU_LOGISTICS'
source_part_id VARCHAR, -- 'BR-4471-A', '4471A', ...
owning_party VARCHAR -- accountability tag
);Now a recall query joins on master_part_id and catches all four aliases at once. Without it, the warranty system's 04471-AA is invisible to the recall built on 4471A.
Industry note: the GS1 standards provide global identifiers (like the GTIN) increasingly used to reduce exactly this alias chaos in automotive parts. Treat vendor-neutral standards as your default canonical key when one exists.
Data lineageData lineageData lineage maps how data moves and transforms across systems, from origin to consumption, showing where it came from, what changed it, and where it goes.Voir la définition complète → is the documented path a value travels: source system, every transformation, and every destination.
Ask a concrete question: the golden record says the caliper's torque spec is 120 Nm. Where did that come from?
Good lineage answers instantly: Tier-1 CAD system → PPAP document v3 → OEM engineering import (2025-11-04) → part_master. Bad lineage means an engineer spends a day in emails and still guesses.
Lineage matters most during three events:
1. Recalls: regulators want the chain of custody for a defect. In the US that is the NHTSA (National Highway Traffic Safety Administration); in the EU, type-approval authorities under the framework regulation. They ask which VINs got the affected part. Lineage plus the alias table produces that list.
2. Warranty disputes: a Tier-1 supplier is charged for a failure. Lineage shows whether the failed part's spec matched what the supplier shipped, or whether the OEM changed the spec after approval.
3. Engineering changes: when the spec changes, lineage shows every downstream system that must be updated.
🎬 [VIDEO: "What is Data LineageData LineageData lineage maps how data moves and transforms across systems, from origin to consumption, showing where it came from, what changed it, and where it goes.Voir la définition complète →?" - youtube.com - a clear 6-minute primer on source-to-target tracing and why it matters for audits]
A golden record decays the moment you stop measuring it. A data stewarddata stewardA business-side owner responsible for the quality, consistency and appropriate use of data in their domain.Voir la définition complète → is the named person accountable for quality in a domain (parts, VINs, dealers). Give them KPIs, not vibes.
Core stewardship metrics, with illustrative targets. Treat all numbers below as example targets to negotiate internally, not industry benchmarks:
Suppose in one month your Tier-1 ingestion receives 40,000 part records. Entity resolution auto-matches 37,600 to an existing master ID. A steward manually matches 1,800 more. 600 remain unmatched (new or ambiguous parts).
Auto match rate = 37,600 / 40,000 = 94.0 percent.
That is just below a 95 percent target. The 2,400 non-auto records are your steward's workload. If each manual match takes 4 minutes, that is 1,800 × 4 = 7,200 minutes, roughly 120 steward-hours that month. Now you can staff the function with real numbers instead of guessing.
Track match rate over time. A sudden drop usually means a source system changed its format without telling you, which is a lineage and governance failure you want to catch in days, not quarters.
Vérification des acquis
1. When the same physical brake caliper appears under four different identifiers across the supplier, OEM, warranty, and logistics systems, what is the fundamental problem this creates?
2. According to the lesson's ownership rule, why does the Tier-1 supplier own the engineering dimensions and material spec rather than the OEM?
3. The lesson distinguishes data ownership from data storage. What is the key difference?
4. Select ALL correct answers about the roles of the four disciplines described in the lesson (governance, MDM, lineage, stewardship KPIs).
Sélectionnez toutes les réponses correctes.
5. Select ALL correct answers about how identifiers and data flow across the OEM-supplier-dealer chain.
Sélectionnez toutes les réponses correctes.
Governance is a data problem wrapped in a power problem.
OEMs sit at the center and have historically dictated data formats to suppliers. Large automakers (Volkswagen, Toyota, General Motors, Stellantis, Ford, and others) run supplier portals where Tier-1s must submit data in the OEM's schemaschemaA schema is the formal blueprint that defines how data is structured, named, typed, and related within a database, file, or message.Voir la définition complète →. That gives the OEM leverage to define the canonical part number.
But dealers are often independent businesses, not owned by the OEM. In the US, franchise laws (state-level dealer franchise statutes) protect that independence. So the OEM cannot simply command dealer data qualitydata qualityThe degree to which data is fit for purpose: accurate, complete, consistent, timely, valid and unique. Poor quality data undermines analytics, reporting and AI.Voir la définition complète →. It has to incentivize it, often by tying warranty reimbursement to clean repair-order data.
The practical result: the OEM usually owns the master part identity, the Tier-1 owns the engineering truth, and the dealer's cooperation must be earned through data-sharing agreements. Your governance model has to respect that no single party controls the whole chain.
Two real regimes raise the stakes:
Governance is not paperwork. It is what lets you answer a regulator in hours.
For one caliper, the full loop looks like this: the Tier-1 owns and submits the spec, MDMMDMMaster Data Management (MDM) is the discipline of creating and maintaining a single, consistent, trusted version of an organization's core business entities like customers, products, and suppliers.Voir la définition complète → resolves the four aliases into master ID MP-100293, lineage records the source of every field, and a steward watches the KPIs so the golden record stays above target. When the recall comes, one query on the master ID reaches every alias, every VIN, and every dealer.
That is the difference between a controlled recall and a chaotic one.