. ET stage (design verification stage): In the early stage of model development, the design company verifies and corrects the accuracy of the body in white and the accuracy of each space.

2. PT stage (production verification stage): After passing the design verification of the design company, the online operation of the body can be performed during the small batch production process

Verification and improvement stage of performance, parts quality and packaging standardization.

3 SOP stage (mass production stage): After all verifications are completed without problems, mass production will begin.

These two terms are generally only mentioned in the Nissan ANPQP document. et--means engineering trial production. This stage requires the tooling and molds to be standardized, which is the product submitted at this stage. Regular tooling molds must be used for production, and general packaging also requires regular packaging, except for special ones. And pt---is production trial production. This stage requires process formalization, which means using the process route and requirements of mass production for product trial production to verify whether it can meet the requirements of mass production. If it is ok, you can proceed to SOP. .