This package introduces a graphical design method that aims to let the reader centre or adjust the specifications of their design in order to achieve the best overall system performance. The book also aims to help improve the speed, cost-effectiveness and quality of designs using the mu-sigma graph technique, a design method that shows how to use computer simulation to identify internal system requirements and relate a parameter's mean value to its allowed standard deviation. It presents a methodology for determining failure rates for non-Gaussian distributions, explores various computer modelling techniques, and process capability indices, and examines the relationship between mu-sigma graphs and the conventional Taguchi methods of quality improvement.