Select regional store:

IT Service Management (ITSM)

IT Service Management (ITSM) refers to a set of processes and functions that help align IT with organizational goals. ITSM methodologies are process-driven and focus on how the services provided by IT meet the developing needs and quality requirements of the organization.

This page discusses approaches to ITSM, including ITIL® and ISO20000, and features links to available resources.

Service Level Agreements (SLAs)

Service level agreements (SLAs) are at the heart of ITSM and are used to describe agreed levels of service between a service provider and a customer. SLAs are applicable both inside and outside an organization and must contain clearly defined levels of service that must be capable of measurement and must be directly relevant to the effective performance of the service supplier.

Service level management ensures that service levels within SLAs are monitored and, if they are not met, that the relevant processes are informed so that they can take the appropriate actions.

The SLA must be agreed by both parties. SLAs are not a stick that one organization can use to beat another, and they are not the solution to poor existing service. Poor performance issues have to be resolved—and a clear future level agreed—before an SLA can be drafted and agreed.

ITIL® and IT Service Management

Developed by the UK’s Cabinet Office (previously the Office for Government Commerce or OGC), ITIL® is a best-practice methodology for managing IT as a service, and it is the most widely used approach for IT Service Management in the world, adopted by corporations including Disney, NASA, HSBC, and HP.

See our ITIL® information page for more in-depth guidance and our ITIL® Web Store for all available products and resources, including books, toolkits, and training courses. IT Governance has the largest stock holding of ITIL® books in North America, including all available formats of the official TSO books.


There are five core ITIL® books:

  • ITIL® Service Strategy provides guidance on how to design, develop, and implement service management not only as an organizational capability but also as a strategic asset.
  • ITIL® Service Design provides guidance for the design and development of services and service management processes.
  • ITIL® Service Transition provides guidance for the development and improvement of capabilities for transitioning new and changed services into operations.
  • ITIL® Service Operation describes best practice for managing services in supported environments.
  • ITIL® Continual Improvement provides practical guidance in evaluating and improving the quality of services, overall maturity of the ITSM service lifecycle, and its underlying processes.

All five volumes are available in the ITIL® Lifecycle Publication Suite, in hardcopy, online subscription, and multi-user license formats.

ISO 20000 and IT Service Management

Although ITIL provides a basis for IT service management, the development of an international standard for IT Service Management, ISO/IEC 20000, has been crucial to the long-term adoption of IT service management around the world.

Comprising five parts, ISO 20000 provides a series of best-practice recommendations for ITSM to help organizations benchmark how they deliver managed services, measure service levels, and assess their performance. It is broadly aligned with, and draws strongly on, ITIL®.

The main benefit of using ISO 20000 as a basis for IT Service management is that it provides a structured framework for service measurement and improvement and allows for independent assessment and external verification of an organization's ability to meet customer requirements.

Some of the most common uses of ISO 20000 by organizations are:

  • for the quality assurance of service providers
  • for assurance of the ability of service providers
  • for assurance of the consistency of service provision
  • for assurance of a service provider’s ability and intention to review processes and services
  • to implement a best practice Service Management System
  • to monitor the effectiveness of their delivery of managed services.

ISO/IEC 20000 Standards and frameworks

ISO 20000, the international service management standard, enables organizations to ensure that their IT service management processes are aligned with their business needs and with international best practice. The standard comprises five parts:

  • ISO/IEC 20000-1 specifies the requirements for a service management system (SMS) and details requirements for the service provider to plan, establish, implement, operate, monitor, review, maintain, and operate an SMS.
  • ISO/IEC 20000-2 allows a better understanding of the requirements of ISO20000-1, enabling better deployment, adoption and use of an SMS within an organization, and making it easier to achieve registration.
  • ISO/IEC 20000-3 provides guidance on scope definition and the applicability of ISO20000-1.
  • ISO/IEC 20000-4 details a process reference model (PRM) that provides a high-level description of the service management processes within ISO 20000-1.
  • ISO/IEC 20000-5 is an exemplar implementation plan providing guidance on how to implement an SMS to fulfil the requirements of ISO 20000-1.

ITSM Books

For those new to ITSM, we recommend the following books:

  • ISO/IEC 20000: A Pocket Guide provides an overview of the standard for anyone new to ISO 20000. It explains qualification programs, registration schemes and the interrelationship of ISO 20000 with other standards, such as ISO 27001. The overall emphasis of the guide is on ISO 20000's customer-driven approach to ensure your IT service management processes align with the needs of your business.
  • Implementing Service Quality based on ISO/IEC 20000 offers practical advice and recommendations on how to prepare for audit and implementation, making your registration journey as smooth as possible.
  • Ten Steps to ITSM Success provides a detailed and practical guide to implementing ITSM best practices in an organization, based on the authors' real-world experiences.
  • Practical IT Service Management explains how to set up a technical service management structure, using the best practice framework established by the latest version of ITIL®.
  • The Definitive Guide to IT Service Metrics provides comprehensive, current guidance on how best to tackle the critical subject of continuous improvement, a cornerstone of effective IT service management that is fundamentally dependent on gathering and using meaningful measurements (metrics).

Speak to an expert

Please contact us to discuss your ITSM needs using one of the methods below.

This website uses cookies. View our cookie policy