Prepare a trustworthy sample
Ask a catalog specialist to select 20–30 real parts from your store: common sellers, similar codes, superseded numbers, items with fitment qualifiers and products with incomplete data. Keep the source part ID, brand, code, category, current stock and the evidence for each vehicle application. Use a staging catalog if the production feed changes while you test. Record its export date and the search index date.
Separate an exact identifier match, a documented interchange and a verified vehicle application. They answer different questions. A part can be discoverable by a related number without being confirmed to fit the buyer's vehicle.
Run the parts query matrix
Fill the worksheet with your own part numbers and vehicle examples. For each row, save the result IDs and evidence shown to a shopper, not only a pass/fail flag. Run the same set on desktop and mobile where those interfaces differ.
| Case | Example query type | What to inspect |
|---|---|---|
| Exact code | Full OEM or supplier number | Requested item first; code and brand visible |
| Code variant | Same code with spaces or separators changed | Same item, with normalization recorded |
| Near collision | A code differing by one character | Never silently substitute the other part |
| Interchange | Known replacement number | Relationship and its source are visible |
| Vehicle + part | Year, make, model and part type | Only verified applications presented as compatible |
| Qualifier | A vehicle with an engine or trim exception | Qualifier retained; uncertain fitment marked clearly |
| Stock change | Known item after an availability update | Shown stock matches the agreed source and delay |
| No fitment | A vehicle with no verified matching part | No invented compatible result |
Also test a deleted SKU, an out-of-stock part, a brand spelling variant and a generic category query. For a code with punctuation, compare exact input, spaces removed and separators changed. Preserve the original query in the test record so a normalization bug is reproducible.
Verify fitment separately
For every vehicle result, inspect the underlying application record: year, make, model, engine, position and qualifiers as applicable to that product. Ask the catalog owner to resolve ambiguous and negative cases. Do not convert “possible match” into a confirmed-fit badge to make the pilot look better.
In North American aftermarket catalogs, ACES and PIES provide standardized exchange formats for fitment and product data. The Auto Care Association explicitly says that ACES and its vehicle database do not create your product's fitment data: you must research, create or obtain it. Check the source, coverage, license and update cycle before proposing a year/make/model or VIN-led interface.
Set acceptance rules
Agree on rules before viewing the results. The numbers below are suggested pilot gates, not measured performance or a universal SLA. Adjust the speed and coverage thresholds to your catalog and device mix, but keep the safety rules explicit.
- All selected exact-code queries return the requested item first.
- No near-collision or missing-fitment case is labelled as confirmed fit.
- Every interchange shown has a traceable source and relationship type.
- Stock and price reflect the agreed source within the signed-off update window.
- Measure response time on the same device and network; record the median and slowest case.
- Catalog specialists sign off on the false positives, not just the search team.
Keep two failure lists: search behavior (normalization, ranking, filters or stale index) and catalog data (missing interchange, fitment or qualifier). This distinction determines who can fix the issue and what a vendor can responsibly promise.
Download the worksheet
Download the auto parts search pilot CSV. It contains 16 test cases and columns for expected IDs, fitment evidence, observed results, index age, owner and decision. Replace each placeholder query with a real catalog example. Review the sheet with the person responsible for applications data.
Turn findings into a build scope
Send the completed worksheet, a small catalog sample and your platform details to the team implementing search. Mark which requirements are simple identifier matching, which require catalog cleanup, and which need a licensed fitment feed or custom interface. Our auto parts search page explains how we evaluate those requirements during a catalog pilot. For a cross-industry baseline, use the general site search pilot guide.