More about normal data

The most common application of CUSUMs is controlling the mean of a stream of process data modeled by the normal distribution. The last two chapters illustrated the CUSUM for the mean of normal data; this chapter gives more detail. We look at extensions to the basic method, covering Fast Initial Response CUSUMs, CUSUMs for variance shifts, weighted CUSUMs, and combined Shewhart/CUSUM charting. We also examine the effects of model departures on CUSUM schemes. We begin with a closer look at the mechanics of determining ARLs.