Dr. Deming maintained that quality comes improving the process, not from inspecting the finished goods at the end of the production process, then discarding those items that failed to meet specifications.
He did not advocate the extinction of inspection altogether. He acknowledged that for some industries, high levels of downstream inspection might be necessary (banks, health care providers, certain military and aerospace operations, for example, might do this to ensure safety or reduce risk exposure). Inspection might also be necessary to gather information or to monitor engineering success during quality upgrades.
But, at the finished goods stage, it might be very difficult to determine where a defect took place. It is therefore better to ensure high quality input of raw materials and processes than to wait until the end of the process to find defects.
The Japanese, for example, embraced the notion that decreasing variation decreases total cost, not final inspection. Further, they found that the concept of "meeting specification" was synonymous with "high quality" was incorrect.
Dr. Deming tells the story about two orchestras playing Beethoven's Fifth Symphony: the London Symphony Orchestra and his local hometown orchestra. Both play the same music, the same notes, and employ competent musicians who make no mistakes. But the London Symphony's work is beautiful, and the hometown's simply competent.
"Just listen to the difference".