The term "Defect" is related to the term "Fault" because a fault is a defect, which has not yet been identified.
A process/activity during which a high number of defects occur is known as a defect-prone process.
With the optimizing process, the organization has the means to identify the weakest elements of the process and to fix them.
The data that is available with the optimizing process gives us a new perspective on testing.