I want to thank John Hunter for his excellent comments on zero defects and maybe for somethings it is difficult to be perfect. Two stories:
One involves Dr. Shingo as he walked through one of his client's factories with the CEO of one of their major vendors. The CEO looked around and could not see the quality charts up on the wall and was very disappointed that this plant was not "quality conscious." "How can you claim to be defect free without quality charts?," he declared? The president of the plant said, "I would be happy to put up charts that measures defects but the truth is we don't make any defects."
So what do you want quality charts or zero defects?
About a year ago, I was with my past author Mr. Nakamura who absolutely believes in the concept of zero defects. It doesn't mean that people do not make mistakes, of course they do, but we can evolve a process to develop devices, techniques, that absolutely prevent mistakes from becoming defects.
I was sitting with a friend this week who is now a real estate broker but who used to be a carpenter and asked him, "What kind of device could you make that would not let you put a nail in the wrong place on the wall? He thought for a while and finally came up with, "I would use a template. The template could be designed, made out of metal, that would not allow me to put the nail in the wrong place."
It takes thought. In takes normally a group of people working together on discovering ways to first reduce defects and then to devise devices that would prevent defects from occurring.
Dr. Shingo believed you could do it and he believed you could do without spending much money at all. And remember if you feel it can't be done than, of course, it can't.