Recent and ongoing improvements in computer technology have increased the need for efficient and reliable design tools; computational methods have opened the door to making sensitivity analysis a tractable design tool for industries that design and manufacture high performance products. These industries are increasingly interested in exploiting the advantages of computer-aided design, numerical analysis, and optimal design methods. This book provides an understandable introduction to one approach to design sensitivity computation and illustrates some of the important mathematical and computational issues inherent in using the sensitivity equation method (SEM) for partial differential equations.