ABSTRACT
This chapter describes multivariate process capability indices (MPCIs) designed for such quality characteristics in detail. PCIs for unilateral specification limits have mostly been defined for univariate processes. The MPCIs discussed in this chapter can be used when there are not too many quality characteristics to consider. However, in practice, an industrial statistician or quality engineer may come across processes having considerably large number of a correlated quality characteristics. The MPCIs discussed so far in this chapter, make a common assumption. MPCIs for processes with unilateral specification regions are less explored as compared to those with bilateral specification limits. Thus there remains ample scope of research in this area, starting from defining new MPCIs which are not mere generalization of Cpu and Cpl, to studying properties of new and existing MPCIs and finding out appropriate threshold values of each of the MPCIs.
