HomeCasesThree Sample Rounds, One Root Cause Cases /Factory Sourcing Three Sample Rounds, One Root Cause Three failed samples were read as a factory problem. The real cause was a tolerance left undefined in the specification. 6 min read Reading time October 26, 2026 Updated Factory Sourcing Filed under On this page9 sections Background The problem Scope What we did What we found Deliverables Result Limitations Next step Quick read · Factory Sourcing The third failed sample is usually treated as proof that the factory cannot do the job. Sometimes it is proof that the specification never said what the job was. Typical scenario. Assembled from recurring project patterns, not a single client record. No client name or factory is disclosed. Background Silicone components, new product development, buyer with a design file. Deliverable: sampling follow-up. Timeframe: six weeks. The problem Three sample rounds, three revisions, each rejection on a different point: colour, then hardness, then a fit that was slightly tight. The buyer was ready to change factory. Scope Establish whether the failures were process capability or specification ambiguity, and define confirmation points for the next round. Design changes excluded. What we did The three rejections were compared against the specification rather than against each other. Colour was defined by a name, not a reference sample. Hardness was given as a range wide enough to include two different material grades. The fit dimension had no tolerance at all. None of the three was a factory failure. The factory had produced, each time, something the document allowed. The specification was rebuilt with a colour reference, a single hardness value with tolerance, and a dimension with an explicit limit. A confirmation sheet was agreed before the fourth round: what would be measured, with what instrument, and what would count as a pass. What we found Repeated sample failures are more often a document problem than a capability problem. Changing factory first usually buys the same three rounds again. Deliverables Failure-to-specification mapping, rebuilt specification points, sampling confirmation sheet, and a signed reference sample. Result Fourth round approved without revision; the confirmation sheet became the acceptance basis for mass production. Basis note: the number of rounds reflects this project. It is not a benchmark for how many samples a category needs. Limitations No product, material grade or factory is identified. Where a factory genuinely lacks the process, no specification rewrite will fix it; that case is a different conclusion. Next step If a sample has been rejected twice, send the specification and the rejection notes before changing supplier. Supply chain execution covers sampling follow-up and pre-shipment inspection. Related reading Factory Sourcing Three Weeks, Two Production-Ready Factories A buyer with a fixed launch date and no qualified supp… Read the full case → Factory Sourcing Four Days, Two Cities, Five Plants A route built around one industrial belt instead of th… Read the full case → Factory Sourcing Three Quotes, 40% Apart, Same Product The gap was not negotiation room. It was tooling owner… Read the full case → Same kind of request? Tell us the category, quantity and target city. Scope, schedule and pricing basis reach you within 24 hours. Submit a request
