Statistics Calculations

This is the formula used for Variable charts:

subgroup calculations for x bar, R and S

For the series of subgroups in the analysis range:

For the series of subgroups in the analysis range

For the series of subgroups in the analysis range

Cpm Index

The Cpm index applies only to the Unilateral calculation styles:

  • Unilateral QCI 9310-190 XR: Capability index specified by Honeywell QCI 9310-190 XR. For unilateral geometrical characteristics (Target=0)
  • Unilateral QCI 9310-190 XS: Capability index specified by Honeywell QCI 9310-190 XS for unilateral geometrical characteristics (Target=0)

Capability assessment under these methods is based on the calculated Cpm value exceeding the defined Cpm Threshold .

When 2 tolerances are defined, the Cpm index is calculated based on the following approach:

Calculation of Cpm index