The ARL0 for a Shewhart individuals control chart using the single test, one point outside the control limits is 370, whereas for an EWMA with λ = .1 and K = 2.8 it is 500 (see Figure 2). This is a much better false alarm rate than the Shewhart individuals control chart. Further, if the K value were set to 3, the typical value, then the EWMA false alarm rate would be even better.