In most industrial situations chemical processes operate within "Total Sites", where they are serviced and linked through a central utility system. Established procedures for heat and power integration work well for optimising each process in isolation. However, greater benefits in terms of energy and capital can be obtained by looking at the entire site. Total site integration addresses the task of optimising each process and the utility system in the context of the overall site. Total site integration has only received limited attention. Various attempts have been made to explore the complex interactions between the processes. However the trade-offs between fuel consumption and co-generation have not yet been established. Therefore, design solutions are mainly derived based on intuition. Since a systematic methodology to address the problem does not actually exist, many iterations may be involved in deriving good solutions and attractive design options can be missed. This thesis provides analytical tools that help understand the interactions between site fuel, heat recovery and co-generation. Capital implications are also addressed. Based on these analytical tools, procedures are developed to tackle total site integration problems including retrofits, site expansions and grassroots, in a systematic way. The procedures do not aim to generate a single optimum solution. Developed within the framework of Pinch Analysis, they are based on physical insights and can help engineers obtain good practical solutions. They can be used to scope and screen major design decisions during the conceptual design stage. The concepts developed in this thesis to address process integration in the context of total sites, do not in any way invalidate the existing Pinch Analysis principles for single process optimisation. Rather, being totally compatible to them, they lift Pinch Analysis onto a higher level of perception.