One day the QC manager at a manufacturing plant said “Starting tomorrow we shall have no more defects.”
Nonsense!
You can’t achieve a desired result by exhorting the workers.
You have to study the system that produces the defects and fix those causes. Off-spec materials, worn out machinery, inadequate training, outdated procedures, etc.
Workers can do nothing about those things.
Defects are downstream, the system is upstream. The behavior of a system as a function of time is called a ‘process.’ A process takes certain inputs and delivers certain outputs, days, weeks or months later.
A major-league hitter gets paid millions of dollars to turn out 70% defective work.
A stable process can turn out 100% defective results, day in and day out.
To solve problems, you have to look upstream and improve the process.
Western Horse Watchers Association 