This Handbook is meant to help users to implement the ISO/IEC 20000-1:2018 standard, and describes how to incorporate popular management methods, service management frameworks and certain standards into an IT service management system. It outlines the requirements of a service management system (SMS), which is the combination of management responsibilities, processes, organizational roles and activities to manage services. These services can be of any kind (e.g. healthcare, transport, IT, consultancy services) and be provided by organizations (often known as service providers) of any size (e.g. self-employed individuals, small and medium enterprises, government agencies, commercial enterprises).