ISO 22514-6:2013 provides methods for calculating performance and capability statistics for process or product quantities where it is necessary or beneficial to consider a family of singular quantities in relation to each other. The methods provided here mostly are designed to describe quantities that follow a bivariate normal distribution. In principle, this part of ISO 22514 can be used for multivariate cases.

ISO 22514-6:2013 does not offer an evaluation of the different provided methods with respect to different situations of possible application of each method. For the current state, the selection of one preferable method might be done following the users preferences.

The purpose is to give definitions for different approaches of index calculation for performance and capability in the case of a multiple process or product quantity description.