Zst

For short-term data, Z_ST = Z_TOTAL, expressed as Zst-total,

where

and

is the inverse normal cumulative distribution function, which assumes a right-sided tail.

In Microsoft Excel:

When displaying short-term metrics, Z_STappears as Zst-total. This metric is equal to Z-LSL if there is only a lower specification limit, or Z-USL if there is only an upper specification limit.

For long-term data, Z_ST = Z_LT + ZScoreShift. When displaying long-term metrics, Z_ST appears in the capability metrics table as Zst.

Note:

Z scores typically are reported only for normal data. The maximum value for Z scores calculated by Crystal Ball from forecast data is 21.18.