Get Aggressive with Testing

The Zero-Defect strategy is clearly not about making a defective product from time to time. It is about realizing that something went wrong that will adversely affect the product over its expected lifetime. The error that most manufacturers make is in placing the quality control at the end of the process hoping to cull out all of the defective product. This never works and it never will.

The only effective Zero-Defect program that works is one where the quality is controlled at strategic points along the process. If this is established correctly, there is no need for a QC department at the end of the process except perhaps for verification of the QC functions built into the process, by means of an effective sampling plan.

The problem is that most manufacturers are not willing to invest in the QC along the way. Instead, they simply try to push as much raw material through process as possible and then complain about the outcome when the process tanks. It is the equivalent to being a poor sport.

Many of the Japanese companies have been exceptional at recognizing this approach and they have enjoyed the benefit for quite some time. But they don't try to identify and track each and every process variation that can or will occur. Instead they use the correct approach of understanding what the tolerance band is of each process and they monitor for variation outside that range of variation. When something causes the tolerance to widen or shift, a change has occurred that must be addressed. The problem in most companies is that no effort is put into understanding the tolerance band of certain steps along t he way and the impact that it has on the outcome.

Perhaps one of the most effective programs ever developed is the Failure Mode and Effects Analysis (FMEA) because it makes a good starting point for where to look. By that, I mean to emphasis that even a good FMEA will not cover every combination of screw ups to which most processes are subject. Consequently there will be surprises along the way. What a good FMEA does do is that it usually identifies the parts of the process that have the most influence. The failures come from not knowing what is significant and what is not. That being said, the issue here is tolerance and limits which are often chosen arbitrarily without any reasonable analysis. Effectively detecting variation along the way, that is out of a realistic specification is the only way to approach Zero Defect. Everything else is lip service.

Most processes are monitored in a monthly report. This is a lot like driving a car using only the rear view mirror to see where you have been. You certainly know that you are moving, but you only know for sure where you have been. The goal is to know something about what is happening along the way. For that, you must look forward.