SPC uses two control charts to ensure quality in manufacturing: the sample mean (X-bar) chart and the sample range (r) chart. The control chart limits are established for X-bar and R charts based upon tolerances set during the design stage of the product. In most cases, problems are _________ before any ___________ parts are produced, thus reducing scrap and rework.
a. Diagnosed and resulved / substandard
b. Identified / faulty
c. Solved / defective
d. Identified / new
e. Fixed / defective