Erstmuster

Erstmuster is the first manufactured sample of a product produced according to the final design and production process, intended for evaluation by the customer and internal quality teams. It is produced under controlled conditions to demonstrate manufacturability and to verify that the design can be produced to defined specifications. Unlike a prototype or a pre-series model used for concept validation, the Erstmuster uses the production method, tooling, and tolerances that will be used in serial production.

It supports design validation, process validation, supplier qualification, and customer approval. The customer may issue a Freigabe (release) or request changes; if deviations exist, they are recorded as non-conformities and addressed through rework or redesign before approval for higher volume. After Erstmuster, a second sample (Zweitmuster) or subsequent batches may be produced to confirm changes and readiness for series production. The term is often used in mechanical, automotive, electronics manufacturing and aerospace, and is commonly associated with First Article Inspection (FAI) processes.

Terminology nuance: In German practice, Erstmuster denotes the first article that is made with the final production process, not a pure design prototype; while Muster may refer to any sample, and Prototyp often precedes the Erstmuster. The use and acceptance criteria are defined in project documentation and contractual requirements.