The service lifecycle is an approach to IT service management that emphasises the importance of coordination and control across the various functions, processes and systems necessary to manage the full lifecycle of IT services. The service management lifecycle approach considers the strategy, design, transition,
operation and continual improvement of IT services. The service lifecycle is described in a set of five publications within the ITIL Core set. Each of these publications covers a stage of the service lifecycle (see Figure 1.2) from the
initial definition and analysis of business requirements in service strategy (SS) and service design (SD), through migration into the live environment within service transition (ST), to live operation and improvement in service operation (SO) and continual service improvement (CSI). The term ‘continual’ is used in preference to ‘continuous’ to emphasise that this activity is not performed on a constant basis, but as a series of planned and controlled actions.