Which statement is NOT true?

A highly reliable product is only as good as the inherent reliability of the product and the quality of the manufacturing process.

Even though a product has a reliable design, when the product is manufactured and used in the field, its reliability may be unsatisfactory.

Tool wear describes the gradual failure of cutting tools due to regular operation.

Generally speaking, the presence of assignable causes produces values within the standard deviation of the control limits$.$

All statements are true.