Resolving Engineering Change Notice Divergence between Overseas CAD Models and Local Chinese SOPs
Enforce engineering changes by locking CMM inspection scripts directly to master CAD revisions and withholding tooling sign-off until local SOPs match.
Tooling Sign-off
Meaning
Administrative approvals in the manufacturing process confirm that a custom mold, die, or fixture has been validated and is ready for mass production. A tooling sign-off is executed only after sample parts produced by the tooling have been fully inspected and found to comply with all engineering specifications. This approval shifts the financial and operational responsibility from the tooling fabricator to the production factory.
Dimensional Audit
Inspection of the first articles produced during the trial run provides the empirical data required for this approval. Metrology laboratories measure the physical samples against the engineering drawings using coordinate measuring machines to verify every dimension. If the samples fall outside the specified tolerances, the tooling must be modified, and a new trial run must be conducted.
The final tooling sign-off is delayed until the physical parts demonstrate repeatable compliance over a multi-hour test run.
Supplier Obligation
Fabricators are contractually required to maintain the tooling in optimal condition until the official approval is secured. The sign-off document represents the legal trigger for the final milestone payment to the tooling supplier. Without this signed document, the buyer can refuse payment and demand further adjustments at the supplier’s expense.
Production Release
Authorization to begin mass production is granted immediately upon the execution of the sign-off document. This step ensures that no unverified mold or die is used for commercial production runs.