This white paper offers a quick refresher course on making good quality measurements. It provides an overview of the four-step process involved in designing and characterizing the performance of any test setup, which can greatly increase the chances of building a system that meets requirements and eliminates unpleasant and expensive surprises. The process begins with defining the system’s required measurement performance, followed by the selection of equipment and fixtures, building the system and verifying its performance, and rechecking performance on a regular basis.