This document specifies requirements for an organization to establish, implement, maintain and continually improve a service management system (SMS). The requirements specified in this document include the planning, design, transition, delivery and improvement of services to meet the service requirements and deliver value. This document can be used by: a) a customer seeking services and requiring assurance regarding the quality of those services; b) a customer requiring a consistent approach to the service lifecycle by all its service providers, including those in a supply chain; c) an organization to demonstrate its capability for the planning, design, transition, delivery and improvement of services; d) an organization to monitor, measure and review its SMS and the services; e) an organization to improve the planning, design, transition, delivery and improvement of services through effective implementation and operation of an SMS; f) an organization or other party performing conformity assessments against the requirements specified in this document; g) a provider of training or advice in service management. The term "service" as used in this document refers to the service or services in the scope of the SMS. The term "organization" as used in this document refers to the organization in the scope of the SMS that manages and delivers services to customers. The organization in the scope of the SMS can be part of a larger organization, for example, a department of a large corporation. An organization or part of an organization that manages and delivers a service or services to internal or external customers can also be known as a service provider. Any use of the terms "service" or "organization" with a different intent is distinguished clearly in this document.