The operator compares a new part with the approved sample and finds a match. Later, quality staff discover that the sample belongs to an earlier revision. The comparison was careful; the reference was wrong.
A retained sample is useful only when people know what it represents. Its identity, approval scope and current status need the same attention as the drawing or specification beside it.
Give the sample a traceable identity
Record the part number, revision, approval date, relevant customer or project and the person authorised to approve it. Link the object to the controlled information rather than relying on a handwritten “good” sticker.
ISO’s guidance on documented information for ISO 9001:2015 provides background on maintaining and retaining information. This article uses it as a process reference, not a certification checklist or a claim about which standard edition your organisation currently follows.
State what the sample proves
A colour sample may support appearance comparison without establishing dimensional compliance. A functional prototype may not represent the final material or production process. Write the permitted use and limitations clearly enough that another shift can interpret them.
For example, an illustrative approval might cover visible surface texture while dimensions remain governed by a drawing and inspection plan. Treating the sample as approval of every characteristic would exceed that agreement.
Control changes and deterioration
When a design changes, decide whether the reference must be replaced, relabelled or formally retained as obsolete. Keep superseded items away from the current-use location so physical convenience does not override revision control.
Storage matters too. Light, corrosion, handling and contamination can change a reference over time. Define suitable protection and review intervals for the characteristic being compared. A faded colour chip cannot remain a trustworthy appearance standard indefinitely.
Test the handover with someone new
Ask a trained person from another shift to find the correct sample and explain its purpose using the available record. Any uncertainty reveals a process gap before it becomes a batch-level disagreement.
When a mismatch appears, follow the organisation’s nonconformance and escalation process rather than selecting whichever reference makes the part pass. An approved sample should reduce ambiguity. Giving it a controlled identity keeps it from becoming a confident-looking source of error.