The complete framework of ITIL is based on service lifecycle. Each lifecycle defines certain processes for effective service management.
Service lifecycle helps to amplify the service management approach and to achieve better understanding of its structure. In the coming chapters, we will be discussing all lifecycle individually with their processes and functions.
There are 26 processes and 4 functions in ITIL V3. These processes and functions are discussed in detail with each service lifecycle in further chapters.
A process defines policies, standards, guidelines, activities, and work instructions. It takes some defined inputs to produce desired results.
A function is defined as group of people or tools required to carry out one or more processes and activities.