How to keep reference samples from production batches
Have a buyer-appointed inspector select samples from actual production batches, record their identity and condition, and place them with a named custodian under suitable storage conditions. Preserve unused samples for comparison with later returns. Agree these arrangements with Cambridge China Bridge.
Define what the retained sample represents
An approved golden sample records the agreed standard. A retained production sample records what was actually made in an identified batch. Keep them separately and label their roles clearly. For approval before production, see making bulk production match the sample. This guide covers the physical evidence to preserve after production.
Before the run, agree which batches and variants need representation, who selects the samples, where they will be kept, and who can authorise opening or disposal. Choose quantities around likely examinations and destructive tests, leaving untouched material for later comparison. Record gaps where a retained sample does not represent a material lot, colour or production period.
Put selection under the buyer's control
Make the buyer's quality lead responsible for the retention plan and appoint an inspector to select the pieces. Ask the factory to provide access to finished goods and batch records, rather than sending specially prepared examples. Select across relevant cartons, production stages and material changes. Record the selection method and any access restrictions.
Keep the selected pieces in their supplied packaging where practical. Photograph their condition before sealing, including visible defects. Do not replace an imperfect selected piece with a better example without recording the change. After rework, identify replacement samples separately and preserve the earlier evidence where useful.
Identify the sample and record every handover
Give each retained item a unique reference. Link it to the purchase order, factory, product variant, batch, material lot where available, specification revision, production date and inspection report. Record who selected it, when and where, its carton origin, condition, seal identity and storage location. Put the reference on the protective container without covering original markings.
UK government product-safety guidance stresses traceability after sale for accountability. For retention, make the sample register searchable against the batch identifiers used in stock and sales records. See batch traceability from factory to customer. Record every transfer, opening and resealing, with the responsible person's name and reason.
Choose storage conditions and a review date
Assign a named custodian and a location protected from accidental sale, use or disposal. Follow the product's specified storage conditions. Consider moisture, light, heat, contamination, deformation and packaging compatibility. For sensitive goods, agree monitoring with the supplier or laboratory and record excursions. Avoid adding drying agents or changing packaging unless their effect has been considered.
Agree a retention period for the product before shipment, considering shelf life, expected service life, complaint timing, customer commitments and any applicable product-specific requirements. Set a review date rather than silently discarding samples when space runs short. Record deterioration, authorised disposal and the reason; preserve samples connected with an unresolved complaint.
Use retained samples without overstating the evidence
When a complaint arrives, match the returned product to its batch before opening the retained sample. Photograph the return as received and keep it separate. Compare the return, retained production sample, golden sample and written specification using consistent methods. Record differences in age, use, transport and storage. A sound retained piece does not prove every item in the batch was sound.
Agree the investigation question with the laboratory before destructive testing, and preserve untouched material where practical. Follow laboratory sample chain of custody for transfers and investigating customer returns for the wider complaint process. Use the findings to test possible causes, including manufacturing variation and later damage. Treat a safety concern as urgent while the comparison proceeds.
Frequently asked questions
Who should choose production reference samples?
The buyer's quality lead should approve the plan and appoint the selector. Use an inspector with access to actual batch stock, and record how pieces were chosen rather than accepting factory-prepared examples.
How many reference samples should I keep?
Base the quantity on batch variation, planned examinations and whether tests consume or damage samples. Agree enough material for the investigation while preserving untouched comparison material.
How long should I keep production samples?
Agree a product-specific period considering shelf life, expected service life, complaint timing and applicable requirements. Set a review date and preserve samples linked to unresolved complaints.
Does a good retained sample disprove a complaint?
No. It shows the condition of that selected piece under its recorded history. Other goods may differ, and the return may have experienced different transport, storage or use. Investigate those differences.