It is observed that the early defective rate (EDR) for a type of PCB module is 14% following 30 days installation in the field. The management anticipates the defective rate shall be less than 2% while the actual failure rate is two digits. The defective rate is computed as the ratio of faulty boards to the total boards installed during the first 30 operational days. For example, consider a new system consisting of 20 PCB modules. During the 30-day operation period, three modules are found malfunctioning and replaced by three spare modules. Then the defective rate is 3/20=15%. High defective rate poses a negative image on the system quality with the implication of low reliability perceived by customers. Therefore, the management decides to launch a Six Sigma program to address the high early infant mortality issues.