1. A measurement system cluster for measuring process parameters associated with wafers in a semiconductor fabrication process, comprising: first and second measurement systems having first and second measurement instruments, respectively, wherein the first and second measurement instruments are operative to measure at least one process parameter associated with a wafer; and a wafer transfer system receiving a wafer processed in the fabrication process and selectively providing the wafer to at least one of the first and second measurement systems according to a measurement system selection criteria for measurement therein of a process parameter.