# Warranty root-cause exception case, step by step | SourceX

Canonical: https://refer.sourcex.si/guides/warranty-root-cause-feedback-exception-examples
Last updated: 2026-10-20

The warranty records that explain a hard exception are the ones that show the decision at the branch point: the return findings that said "no fault found", the field service reports that described the site, and the engineering change that acted on the field evidence instead of the bench. This page walks through one fictional case in seven steps, names who decided each step and which record captured it, and ends with how to recognize a similar case at a client.

It is part of the [root cause analysis records page](/data-types/root-cause-analysis-records), which covers 8D and CAPA records in general. This page follows a single case from start to finish.

## The case in brief

Illustrative and fictional. A 290-person maker of commercial combination ovens for restaurant chains releases a redesigned control board. Every board passes the end-of-line functional test. Three to eight weeks after installation, boards at some sites lock up mid-cycle and show a fault code. Over one quarter, 31 warranty claims arrive for the new board.

The hard part: most returned boards work perfectly on the bench. The cause is a site condition, not a part defect. In this case, the ovens share a circuit with large refrigeration compressors, and when a compressor starts, the voltage sag resets the board's processor. Nothing in the factory reproduces it.

## Step by step: who decided, and what was recorded

| Step | What happened | Who decided | Record that captured it | System |
|---|---|---|---|---|
| 1 | End-of-line test passes for every board | Quality engineer | Test log per serial number | Manufacturing execution |
| 2 | 31 claims for lock-ups within 60 days of installation | Warranty administrator approves replacements | Claim records with serial, install date, fault code | Warranty system |
| 3 | 22 of 26 returned boards show no fault on the bench | Returns lab lead proposes closing as no fault found | Return findings with test results | Returns lab database |
| 4 | Aftermarket director holds the closure and asks for site data | Aftermarket director | Decision note on the investigation record | Quality or CAPA tool |
| 5 | Technicians log shared circuits and voltage readings at 14 affected sites | Field service lead assigns visits | Field service reports with site measurements | Field service tool |
| 6 | Firmware adds brown-out recovery; install guide requires a dedicated circuit | Engineering change board approves | Engineering change notice citing the claim cluster | PLM |
| 7 | 3 claims in the 60 days after installation for units installed under the change | Warranty administrator reviews | Claims filtered by install date | Warranty system |

Each step has a person, a decision and a record. That is the shape a reviewer looks for: an initial problem, an authorized action and a checked result.

## Where the case nearly closed wrong

Step 3 is the exception inside the exception. A returns lab that reads only its own results has a reasonable case for closing the investigation: 22 of 26 boards passed. If the aftermarket director had accepted that, the company would have kept replacing good boards at a growing cost, and the record would show a closed case with the wrong conclusion.

What changed the outcome was the decision note in step 4. It is often the smallest record in the chain, sometimes one line in a quality tool or an email, and it is the one most likely to be lost. It shows that someone weighed the bench result against the claim pattern and chose to look further. Without it, steps 5 and 6 look like a separate project rather than the answer to step 3.

The field reports in step 5 then do what bench tests cannot. Regulators recognize the boundary they cover: NHTSA's compendium defines a field report as a written communication from a manufacturer's employee or representative about equipment that has moved beyond the manufacturer's direct control. Under the federal early warning rule, covered motor vehicle manufacturers report warranty claims and field reports by system or component, which shows how seriously the field side is treated as its own evidence. An oven maker is not covered by that rule, but the record types are the same.

## Why this sequence is useful evidence

A model trained or evaluated on business decisions needs more than the final answer. It needs to see the moment of uncertainty and the reasoning that resolved it. This case gives that in a checkable form:

- **A wrong path is on record.** The no-fault-found proposal in step 3 is a plausible mistake, and the chain shows why it was wrong.
- **The decision is attributed.** Step 4 names who held the closure and why, which lets a reviewer judge the call.
- **The cause is evidenced, not asserted.** Site measurements in step 5 support the engineering change in step 6.
- **The result is measured.** Step 7 splits claims by install date, so the effect of the fix can be checked rather than claimed.

How outcome-checked records relate to feedback-based training methods is covered in [what RLAIF is](/proof/what-is-rlaif). The individual record types are covered on the [warranty claims data](/data-types/warranty-claims-data) and [field service histories](/data-types/field-service-histories) pages; the value of this case is in reading them together.

## Recognizing a similar case at a client

Field service integrators and aftermarket consultants hear the signs in ordinary conversation. Listen for these:

| What you hear | What it may point to | Metadata question to ask |
|---|---|---|
| "Most returns come back no fault found." | A site-dependent cause the bench cannot reproduce | Are return findings linked to the claim and serial number? |
| "It only happens at certain customers." | Clustering by site, installer or region | Is the install date and site recorded on each claim? |
| "We changed the install instructions, not the part." | An engineering response driven by field evidence | Does the engineering change cite the claims or investigation? |
| "Our techs wrote it up, but it's in the service tool." | Field reports held in a separate system | How many years of field reports survive, and who wrote them? |
| "Claims dropped after the change." | A measured outcome | Can claims be filtered by install date before and after? |

Ask by description only. Never request claim files, reports or exports. The guide to [assessing field service records and resolution notes](/guides/how-to-assess-field-service-records-and-resolution-notes) goes deeper on the service side.

## Qualification: owners, authority and open questions

The records in a case like this usually sit with three owners: the warranty administrator or aftermarket director for claims, the returns lab or quality lead for findings, and engineering for change notices. Field service reports may belong to the service organization or to independent dealers. None of those people can authorize a licensing discussion on their own. That is the CEO, or the owner in an owner-run company, and in a group, possibly the parent.

The company needs 50+ full-time employees at peak (contractors excluded), a documented operating history, rights to license and an authorized contact. Companies in the U.S., Canada and the EU qualify, as do companies in the UK, Australia, New Zealand, India, Singapore, South Africa, Latin America, the UAE and Saudi Arabia when at least 90% of the data is in English.

What stays unknown until SourceX reviews it: whether dealer-written reports can be included, which customer site details need redaction, whether product liability or litigation files must be excluded, SourceX's current data needs for this record type and any offer. SourceX funds any referral reward separately; it never reduces the company's payout. More manufacturing record types are listed on the [industries hub](/industries).

## Next step

> **Refer a company. Earn up to $100,000.** Default reward: 25% of Actual Supplier Payout, capped at $100,000 cumulatively per referred company. Eligibility and payment conditions apply, and a signed Schedule A or addendum can differ. A lead, meeting or signature alone does not trigger payment.

If a client's aftermarket team can link claims, return findings, field reports and engineering changes for cases like this one, [register as a partner](/register), check the company against [who qualifies](/who-qualifies) and read the [program terms](/terms) before you introduce its decision-maker.

## Sources

- https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-579/subpart-C
- https://static.nhtsa.gov/odi/ewr/Documents/EWRVehicleCompendium.pdf
- https://refer.sourcex.si/terms
- https://refer.sourcex.si/rewards