At Time R, a Process Is Judged Out of Control $\left( 1 , S _ { 1 } \right) , \left( 2 , S _ { 2 } \right) , \ldots \ldots , \left(y , S _ { \mathrm { r } } \right)$

Short Answer

At time r, a process is judged out of control if any of the cumulative sum plotted values $\left( 1 , S _ { 1 } \right) , \left( 2 , S _ { 2 } \right) , \ldots \ldots , \left(y , S _ { \mathrm { r } } \right)$ lies outside the __________; either above the upper arm or below the lower arm.