ISO/IEC 20000-1:2005 defines the requirements for a service provider to deliver managed services. It is based on BS 15000-2, which has been superseded.

It may be used

1. by businesses that are going out to tender for their services;
2. to provide a consistent approach by all service providers in a supply chain;
3. to benchmark IT service management;
4. as the basis for an independent assessment;
5. to demonstrate the ability to meet customer requirements;
6. to improve services.

ISO/IEC 20000-1:2005 promotes the adoption of an integrated process approach to effectively deliver managed services to meet business and customer requirements. For an organization to function effectively it has to identify and manage numerous linked activities. Co-ordinated integration and implementation of the service management processes provides the ongoing control, greater efficiency and opportunities for continual improvement.

Organizations require increasingly advanced facilities (at minimum cost) to meet their business needs. With the increasing dependencies in support services and the diverse range of technologies available, service providers can struggle to maintain high levels of customer service. Working reactively, they spend too little time planning, training, reviewing, investigating, and working with customers. The result is a failure to adopt structured, proactive working practices. Those same service providers are being asked for improved quality, lower costs, greater flexibility, and faster response to customers.

In contrast, effective service management delivers high levels of customer service and customer satisfaction. It also recognizes that services and service management are essential to helping organizations generate revenue and be cost-effective. The ISO/IEC 20000 series enables service providers to understand how to enhance the quality of service delivered to their customers, both internal and external.

The ISO/IEC 20000 series draws a distinction between the best practices of processes, which are independent of organizational form or size and organizational names and structures. The ISO/IEC 20000 series applies to both large and small service providers, and the requirements for best practice service management processes are independent of the service provider's organizational form. These service management processes deliver the best possible service to meet a customer's business needs within agreed resource levels, i.e. service that is professional, cost-effective and with risks which are understood and managed.