In an ideal world, projects would be completed on time, within speciﬁed budgets and to the standards set out in the plans. In practice, any project involves a set of unique problems and constraints that inevitably create complexity and risk. Plans are liable to change as work progresses and each stage in the process may have to be revisited several times before completion. Although projects have boundaries that protect them to some extent from other activities in the environment, external events will affect the project. The rapidly changing environment of health and social care may have significant impact on longer projects and may require not only revision of project plans but also some realignment of objectives. In any project, new issues will emerge as activities evolve. It falls to those leading and managing projects to be aware of events that impact on the project plan (monitoring) and to revise the plans if necessary (controlling).