Abstract

Prevention of defects in the development of new products is a goal of the Item Quality Process at Eastman Kodak Company. Key steps in this process are identification of critical product components and implementation of the Item Quality Plan table. The table for each critical component includes information such as the following. The supplier and team members responsible for the component are listed, as are its critical characteristics and the early aims and tolerances for each characteristic. Then, design and manufacturing engineers and the supplier use this information to negotiate prototype plans. Eventually characteristics in the table receive critical-to-function (CTF) and critical-to-process (CTP) designations. The supplier produces statistical process control data for CTP items and trend data for CTFs. The table also lists frequency of CTF or CTP measurement and the gage or tool number used. This information is the basis for computing a Test Capability Index (TCI) for a given characteristic: TCI = (upper specification - lower specification)/(6*standard deviation of test only). The guideline value for TCI is a minimum of 4.0. The Item Quality Plan table indicates also whether the fabrication process is under control. The process must be stable before process capability work continues. Long-term Cpk data for the component then are plotted on a histogram to show which characteristics need the most attention. Thus, the Item Quality Plan focuses on prevention and optimization of process capabilities.