Quality control

[1] This approach places emphasis on three aspects (enshrined in standards such as ISO 9001):[2][3] Inspection is a major component of quality control, where physical product is examined visually (or the end results of a service are analyzed).

[3] Early stone tools such as anvils had no holes and were not designed as interchangeable parts.

[7] The simplest form of quality control was a sketch of the desired item.

However, manufacturers soon found it was difficult and costly to make parts be exactly like their depiction; hence around 1840 tolerance limits were introduced, wherein a design would function if its parts were measured to be within the limits.

[15] In practice, projects typically have a dedicated quality control team which focuses on this area.