This document discusses the DMAIC methodology for improving tennis skills and performance. DMAIC stands for define, measure, analyze, improve, and control. It is typically used in business to reduce process variation but can also be applied to tennis training. The document outlines how each step of DMAIC can be implemented for the serve, such as defining the target, measuring ball placement, analyzing good versus bad serves, improving technique, and controlling variation through practice. An example is provided of a girl who improved her USTA junior ranking from 194 to 79 through two months of DMAIC tennis training.