This title provides an insight into the rich diversity of techniques, tools and knowledge used in performance engineering, covering the whole life cycle - from design through to operation - of both networks and systems. Performance modelling is discussed as an essential technique, providing the ability to predict performance through a quantitative understanding of how varying demand affects the behaviour of a system or network. Performance testing is discussed as offering the final opportunity to address the concerns of economic pressures pushing the identification and resolution of performances further down the supplier chain....