Power tools collect a wealth of data about the fastening process. With some simple statistical analysis, engineers can obtain valuable insight into the fastening process.
No matter how accurate the tool, there will always be some variation in how much torque is applied to a fastener. Myriad factors influence the process. Variation in air pressure, friction, part dimensions, operator skill and other factors means that one fastener will be slightly tighter or looser than the next. Statistical analysis can tell engineers when such variation is unacceptable.