Viability and capability indexes for multiresponse processes

The viability index Vr is introduced as an intuitively appealing measure of the capability potential of a process. It is related to the well-known index Cp but has some advantages over it. The statistical properties of Vr are readily obtainable and, unlike Cp, it extends naturally to multi-response processes. The multivariate viability index Vrn is defined, discussed and illustrated using an example from the minerals sector.