Service Management Blog

ITIL® 4 Key Terms & Glossary

5 minute read
Joseph Mathenge, Jon Stevens-Hall, Muhammad Raza

In this article, we’ll take a look at key terms within ITIL®, a leading service management framework for IT organizations.

(This article is part of our ITIL 4 Guide. Use the right-hand menu to navigate.)

ITIL: The 8 key terms

Within the ITIL SVS Management Practices, 8 key terms are fundamental in understanding the practices, as well as how they relate with the service value chain activities.

Glossary of common ITIL terms

Now, let’s look at many more words that are part of ITIL. This list will include the eight key terms from above, in alphabetical order.

Note that these key terms are not restricted to their own management practice of origin but apply across multiple practices as a result of value streams and value chain activities. There are many other terms used in ITIL which we will come across in future articles.

Acceptance Criteria

The minimum acceptable requirements of a service component that must be fulfilled according to defined stakeholder expectations.

(IT) Asset

Any valuable component that can contribute to the delivery of an IT product or service.


The ability of an IT service or other configuration item to perform its agreed function when required.

(Learn more about service availability.)


The addition, modification, or removal of anything that could have a direct or indirect effect on services.

(Explore change enablement in ITIL 4.)

Change Model

A framework that can be used to manage any specific type of change that may occur repeatedly.

Configuration item (CI)

Any component that needs to be managed in order to deliver an IT service.

(Compare CIs to assets.)

Continual Improvement

Aligning operations, products and services with strategic business goals on an ongoing basis in context of changing requirements, expectations, challenges and opportunities facing the organization.

(Read about the continual improvement activity.)

Continuous Deployment

Continuously deploying the updated code builds into the production environment as all the previous stages in the software development lifecycle (SDLC) pipeline have passed.

Continuous Integration

Continuously merging code changes from multiple sources to a central software build system using automation tools, making the updated build ready for delivery into the production environment.

Continuous Delivery

Continuously making all code changes from the updated software build ready for release into the production environment.


Directing the flow of operations to manage risk, fulfil a business objective or follow a framework guideline.

Customer Experience (CX)

The perceived value of functional and emotional interactions of a product or service with the end-user.

Design Thinking

A human-centered cognitive and strategic process used to develop products and services; prioritizing end-user expectations above business goals.


The set of practices, tools and cultural philosophies that combine development and IT operations tasks to deliver high quality software products faster while reducing waste processes in the SDLC pipeline.

Digital Transformation (Dx)

Modernization of IT to develop new digital business models and reinvent business processes, operations, culture, and end-user experiences.

(Read our comprehensive Dx explainer.)


Any change of state that has significance for the management of a service or other configuration item.

(Learn about ITIL event management.)

Feedback Loop

A model that incorporates the findings or output of a system as one of the input parameters.


An operational framework adopted to control and manage operations, risk, and opportunities.

Guiding Principles

A baseline and definitive set of guidelines applicable to all organizations, despite their varied structure, strategies, goals and circumstances.

(Know the 7 Guiding Principles of ITIL 4.)


The identification of an entity in an IT system that provides them with appropriate rights and privileges.


An unplanned interruption to a service or reduction in the quality of a service.

Known error

A problem that has been analyzed but has not been resolved.


The idea of optimizing system performance by reducing waste processes and leveraging opportunities for efficiency.


The full set of recurrent stages through which a project, product, or services transitions over the course of its lifetime.

(Understand the ITIL lifecycle.)


The simplicity and convenience of maintaining, modifying, updating, troubleshooting, or replacing a system component.


The measure of dependability, efficiency and effectiveness of a system or functional performance on a business activity.

Mean Time Between Failures (MTBF)

The average time duration between two successive failures of a system.

Mean Time to Restore (MTTR)

The average time it takes for a system to restore functionality to optimum levels following a failure incident.

Minimum Viable Product (MVP)

A product depicting the minimum set of features and functionality to satisfy baseline customer expectations and providing the necessary user feedback.

Organizational Resilience

The ability of an organization to prepare for and respond to a change incident while minimizing the impact as it returns to an optimal performance state following the incident.

Organizational Velocity

The efficiency and speed of business operations including production times, response to incidents and risks, and agility in adapting to changing market conditions.


A cause, or potential cause, of one or more incidents.

(Learn about reactive vs proactive problem management.)


Documented information describing the tasks performed and results achieved for a certain function or activity.


A feature, configuration item or service component made available for use in a production environment.

Request for Change

A formal request for implementation of a change and initiating the necessary change control process.


A potential event or uncertainty that can disrupt system performance.

Service Architecture

A conceptual model that describes the structure, behavior and interactions of a collective set of system components and services.

Service Design Practice

A set of processes that can deliver capacity for action or functionality to particular users to perform specific activities.

Service Management

The set of activities performed by an organization to develop, deliver, operate and maintain IT services for its end-users.

Service Value System

The architecture of ITIL 4 that maps all elements and capabilities necessary to manage a service efficiently and effectively. This model describes the activities and components that work together as a system to deliver value to the IT organization.

(Learn more about the service value system.)


The documented requirements and guidelines for a system, product, configuration item, or services.

Standard Change

A low-risk and repetitive change activity that is pre-defined and approved by appropriate governing authorities.

System Thinking

A holistic approach to manage a system or a service organization, accounting for all underlying components, their structure, and interactions with each other.

Technical Debt

A backlog of tasks accumulated over time as alternatives or workaround solutions are implemented instead of resolving the backlog task items.


The measure of work performed by an organization, team, service, or a system over a specific duration of time.


A unit of activity or functional task performed between two system components.


The functionality of a system, service or product aimed at fulfilling a particular requirement. The functionality must support business performance or reduce a constraint, or both.


Confirmation of a system performance relative to specified requirements or expectations.

Value Stream

The set of tasks performed to create and deliver value to the end-user.


A solution that eliminates the impact of a change or incident intended as a temporary replacement to a full resolution expected at a later stage.

Related reading

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About the author

Joseph Mathenge

Joseph is a global best practice trainer and consultant with over 14 years corporate experience. His passion is partnering with organizations around the world through training, development, adaptation, streamlining and benchmarking their strategic and operational policies and processes in line with best practice frameworks and international standards. His specialties are IT Service Management, Business Process Reengineering, Cyber Resilience and Project Management.

About the author

Jon Stevens-Hall

Jon Stevens-Hall is a Principal Product Manager for BMC Helix ITSM. He was a contributing author on several of the ITIL 4 Managing Professional books (“Create Deliver and Support”, and “High Velocity IT”). His work focuses on innovative new tooling for Service Management, and the evolution of ITSM in the DevOps era.

About the author

Muhammad Raza

Muhammad Raza is a Stockholm-based technology consultant working with leading startups and Fortune 500 firms on thought leadership branding projects across DevOps, Cloud, Security and IoT.