White light measurement: a catalyst for change in automotive body dimensional validation. Measurement strategies for stamping and body assembly from tryout through PPAP

Abstract

This report examines the usage of 3D non-contact white light (WL) measurement technology and how its adoption could impact traditional North American automotive body dimensional evaluation strategies from die tryout through PPAP. The report includes several WL measuring studies involving a longitudinal analysis of door components and their resultant assembly throughout the preproduction process. It provides several recommendations for new part measurement strategies and business processes for automotive body stamped parts and subassemblies. The recommendations support a part quality evaluation process that places a greater emphasis on measuring overall part shape and feature conformance as well as intra-panel correlation patterns (e.g., twists and feature-to-feature relationships) versus process capability conformance of discrete points to individual specifications. These recommendations include adopting percent in specification metrics such as PIST, reducing measurement sample sizes for both tryout runs and PPAP, and utilizing new methods for analyzing and reporting part dimensional data. These new methods are aimed at providing more comprehensive part quality representation to increase the utility of dimensional measurement data for end-users.