As previously stated, the ITIL editions have evolved over the years. Each rendition builds on the guidance of previous versions.

ITIL

The British Government developed and released the original iteration of ITIL in 1989.

ITIL 2

ITIL v2 was released in 2000 by Great Britain's Office for Government Commerce (OGC), which absorbed the CCTA that year.

ITIL 3

The OGC released ITIL v3 in 2007. Version 3 upgraded ITIL version 2 by adding process improvement, a stronger service lifecycle approach and more processes for aligning business needs and IT. ITIL v3 introduced 5 stages (service strategy, service design, service transition and continual service improvement), including 26 ITIL processes.

In 2014, ITIL became the property of AXELOS, a joint venture between the Cabinet Office and Capita PLC.

ITIL 4

AXELOS launched ITIL 4 in 2019. In 2022, AXELOS (which was acquired by PeopleCert in 2021) discontinued ITIL 3 and integrated its service lifecycle stages and processes into ITIL 4’s categories and practices.

Fully rolled out in 2023, ITIL 4 represents a significant overhaul of the Foundation, focusing on value-centered end-to-end service. This latest evolution centers on fostering digital transformation in the digital era dominated by cloud computing, hybrid cloud, artificial intelligence (AI) and other technologies. ITII 4 also offers a holistic approach that focuses on value and aligns with agile DevOps philosophies.   

The ITIL 4 contains seven guiding principles for continual improvement¹:

1. Focus on value
2. Start where you are
3. Progress iteratively with feedback
4. Collaborate and promote visibility
5. Think and work holistically
6. Keep it simple and practical
7. Optimize and automate

ITIL 4 consists of 34 practices that are grouped into 3 main categories:

1. General management practices
2. Service management practices
3. Technical management practices

1.  General management practices

The ITTIL 4 general management practices apply across the organization beyond IT services and include these 14 practices:

• Strategy management
• Portfolio management
• Architecture management
• Service financial management
• Workforce and talent management
• Continual improvement
• Measurement and reporting
• Risk management
• Information security management
• Knowledge management
• Organizational change management
• Project management
• Relationship management
• Supplier management

2. Service management practices

The ITIL 4 service management practices focus on the core delivery of IT services and include these 17 practices:

• Business analysis
• Service catalog management
• Service design
• Service-level management
• Availability management
• Capacity and performance management
• Service continuity management
• Monitoring and event management
• Service desk
• Incident management
• Service request management
• Problem management
• Release management
• Change enablement
• Service validation and testing
• Service configuration management
• IT asset management

3. Technical management practices

The ITIL 4 technical management practices cover the technical aspects of IT service delivery and include these three practices:

• Deployment management
• Infrastructure and platform management
• Software development and management

ITIL clearly distinguishes between "incident management" and "problem management."  

Incident management

An ITIL incident is an unplanned interruption in service and incident management is used to restore service. For example, if a network node fails and reduces throughput, that would be classified as an incident. The goal of incident management is to restore service as quickly as possible.

The incident management process focuses on determining the root cause of an incident. If multiple events are co-occurring, incident management can help determine whether all of those events are part of the same incident or distinct from each other.

Implementing ITIL incident management can help improve service levels and meet service level availability requirements or a specified service level agreement (SLA).

Problem management

Problem management examines the root cause of a problem, what actions to take and which resources can help prevent it from happening again.

The following are problem management steps:

• Raise a problem management case.
• Categorize and prioritize issues.
• Systematically investigate (root cause analysis).
• Identify changes needed to resolve and work with change management.
• Verify the problem resolution.
• Close out the problem.

The ITIL 4 certification scheme can be adapted to the learning requirements of the individual and the organization. It uses a modular, tiered approach to allow users to develop a comprehensive view of service management or to focus on specific knowledge areas.²

ITIL 4 Foundation

ITIL 4 Foundation provides the fundamentals, introducing an end-to-end operating model for creating, delivering and continually improving technology-enabled products and services.

Once the Foundation certification is complete, ITIL offers the following four certification streams.

ITIL 4 Managing Professional (ITIL MP)

The ITIL 4 Managing Professional is a stream of four modules that offer critical skills to run successful IT-enabled products and service.

1. Create, Deliver and Support: This module encompasses core service management and service creation.
2. Drive Stakeholder Value: This module is for IT professionals who want to foster relationships with stakeholders to co-create value.
3. High-Velocity IT: This module is for IT professionals who work in digital or highly automated environments or who deliver digital products and services.
4. Direct, Plan and Improve: This module is for those who need to align their team's objectives with organizational strategy.

ITIL 4 Strategic Leader (ITIL SL)

The ITIL Strategic Leader stream consists of two modules that help IT leaders understand the complexities of the digital era and prepare for digital transformation:

1. Direct, Plan and Improve: As in the previous section, this module is for those who need to align their team's objectives with organizational strategy.
2. Digital and IT Strategy: This module provides guidance for crafting a digital vision and shaping IT and business strategies.

ITIL 4 Practice Manager (ITIL PM)

The Practice Manager stream provides shorter and more flexible training. It can also bundled with other modules.

ITIL 4 Extension Modules

The ITIL 4 Extension Modules is a stream of four modules that provide guidance on emerging technologies and how they impact operations. 

1. ITIL 4 Specialist: Sustainability in Digital and IT: This module provides an understanding of sustainability challenges that are related to digitally enabled services.
2. ITIL 4 Specialist: Acquiring & Managing Cloud Services: This module provides vendor-neutral guidance about the value of cloud procurement and technology.
3. ITIL 4 Specialist: Business Relationship Management: This module is for those interested in maintaining and cultivating relationships between service providers and consumer organizations.
4. ITIL 4 Specialist: IT Asset Management: This module is for IT professionals who deal with asset management-related issues (for example, costs and risks, compliance and governance of IT assets).

ITIL 4 Master

The Master certification is the highest achievement of the ITIL certification scheme. It requires candidates to have achieved the Practice Manager, Managing Professional and Strategic Leader certification levels.