Which of these patterns on a control chart would require a worker to stop the process and investigate for an assignable cause?
A)a run of five points alternating up and down
B)a run of three consecutive points above the center line
C)two out of three points close to the center line
D)one point below the lower control limit

Question

Quizplus · Accepted Answer

One point below the lower control limit on a control chart indicates that the process variation is not due to random chance but rather to an assignable cause. This is a signal that there is something specifically wrong with the process that needs investigation and correction.

Which of These Patterns on a Control Chart Would Require