  Process capability index (PCI) is a commonly used statistic to measure
ability of a process to operate within the given specifications or to produce
products which meet the required quality specifications. PCI can be univariate
or multivariate depending upon the number of process specifications or quality
characteristics of interest. Most PCIs make distributional assumptions which
are often unrealistic in practice.
  This paper proposes a new multivariate non-parametric process capability
index. This index can be used when distribution of the process or quality
parameters is either unknown or does not follow commonly used distributions
such as multivariate normal.
