This document discusses translating customer needs or Voice of the Customer (VOC) into measurable Critical to Quality (CTQ) metrics. It defines VOC, CTQ, and how a COPIS diagram can help identify relationships between process outputs (Big Y), performance metrics (Little Y) and input factors (X) that influence the outputs. An example COPIS is provided to illustrate how customer feedback can be translated into CTQs and metrics to measure and improve the key aspects of a process that satisfy customers.