Manufacturing errors are typically a result of missed process steps, mis-set work pieces, faulty machine operation, adjustment errors, setup errors, or bad tool or fixture preparation. Eliminating product defects through error-proofing will yield better quality, lower costs, better predictability, less rework and redundant inspections, improved scrap rates, and reduced variability, because the part will be manufactured right the first time.
How Error-Proofing Relates to Lean Manufacturing
Because it aims to reduce defects, error-proofing is a key component of lean manufacturing. Error-proofing impacts every area of lean manufacturing, including inventory, processing, correction, overproduction, motion, material movement and waiting. In short, error-proofing and lean manufacturing both aim to eliminate any activity outside the normal value stream.
For example, the results of error-proofing can easily be seen in the area of overproduction. Manufacturers may make the decision to overproduce a part because a certain scrap rate is expected.
In this case, manufacturers have introduced more waste into the process. Effective error-proofing can eliminate the need for overproduction by producing the parts correctly the first time.