Sensitivity analysis should be considered a pre-requisite for statistical model building in any scientific discipline where modelling takes place. For a non-expert, choosing the method of analysis for their model is complex, and depends on a number of factors. This book guides the non-expert through their problem in order to enable them to choose and apply the most appropriate method. It offers a review of the state-of-the-art in sensitivity analysis, and is suitable for a wide range of practitioners. It is focussed on the use of SIMLAB - a widely distributed freely-available sensitivity analysis software package developed by the authors - for solving problems in sensitivity analysis of statistical models. Other key features: * Provides an accessible overview of the current most widely used methods for sensitivity analysis. * Opens with a detailed worked example to explain the motivation behind the book. * Includes a range of examples to help illustrate the concepts discussed. * Focuses on implementation of the methods in the software SIMLAB - a freely-available sensitivity analysis software package developed by the authors. * Contains a large number of references to sources for further reading. * Authored by the leading authorities on sensitivity analysis.