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Availability Management

Updated: Apr 25



The primary goal of the Availability Management practice is to ensure that IT services achieve agreed-upon levels of availability to meet the business needs of customers and users.

This practice is instrumental in ensuring services are available and capable of performing their required functions under agreed conditions, thus supporting the organisation's strategic goals.


Availability Management is integral throughout the lifecycle of IT services, from design and development to deployment and ongoing maintenance. It intersects various ITIL practices, ensuring that availability considerations are embedded in all service management aspects.

Key Benefits

Implementing effective Availability Management brings several benefits, including:

  • Enhanced Service Reliability: Reduces service disruptions, increasing reliability and trust in IT services.

  • Optimised Resource Utilisation: Ensures optimal use of IT resources to maintain service availability without over-provisioning.

  • Improved Customer Satisfaction: Minimises downtime, which enhances user experience and satisfaction.

  • Risk Reduction: This helps identify and mitigate potential issues that could affect service availability, thus reducing overall business risk.

Basic Concepts and Terms


In the context of ITIL 4, availability is defined as the ability of an IT service or other configuration item to perform its agreed function when required. This capability is a critical service management component and directly impacts user satisfaction and business performance.

Vital Business Functions (VBFs)

A Vital Business Function (VBF) is an activity or process critical to the business's success that must be supported by adequately high levels of availability. Identifying these functions is crucial in prioritising resource allocation and applying appropriate availability controls. For instance, for an email service, VBFs would include sending, receiving, and accessing archived messages, while less critical functions like calendar access may have lower availability requirements.

Key Terms and Concepts

  • Mean Time Between Failures (MTBF): This metric indicates the average time between service failures, providing insight into the reliability of a service.

  • Mean Time to Restore Service (MTRS): This measures the average time to restore a service after a failure occurs, reflecting the service's resilience and the efficiency of recovery procedures.


Availability Management in ITIL 4 involves a structured approach to ensuring services meet their agreed availability levels. The practice consists of several key processes that contribute to maintaining and improving service availability.

Establishing Service Availability Control

This process begins with identifying and agreeing on service availability requirements, which are influenced by business needs and customer expectations.

Key activities include:

  • Identifying Service Availability Requirements: Analysing customer requirements and determining essential service levels to support vital business functions.

  • Agreeing on Service Availability Requirements: Formalising these requirements into service level agreements (SLAs) with clear availability targets.

  • Designing Availability Metrics and Reports: Establishing how availability will be measured and reported, ensuring metrics reflect the actual availability as experienced by users.

Analysing and Improving Service Availability

Post-establishment, continuous analysis and improvement are vital to adapt to changing business environments and technology landscapes.

Activities in this process include:

  • Monitoring Service Availability: Continuous tracking of service performance against agreed metrics to identify deviations or potential improvements.

  • Service Availability Analysis: This involves using data gathered from monitoring to analyse trends, perform root cause analysis of failures, and identify potential areas for improvement.

  • Planning and Implementing Improvements: Based on the analysis, corrective actions and enhancements are planned to improve service availability.

Relationship with Other Practices

Availability Management is not an isolated practice within the ITIL framework; it is closely interconnected with several other ITIL practices to ensure comprehensive service management. Understanding these relationships is crucial for a holistic approach to service delivery.

Integration with Other ITIL Practices

  • Service Level Management (SLM): Works directly with Availability Management to define and manage SLAs that include specific availability targets. SLM ensures that these targets are aligned with business needs and customer expectations.

  • Incident and Problem Management: These practices are essential for resolving incidents affecting availability and identifying underlying problems that could lead to potential availability issues.

  • Change Enablement: Availability Management must assess the impact of proposed changes on service availability to ensure that changes do not adversely affect service levels.

Distinction from Service Continuity Management

While both practices aim to ensure service reliability, their focus areas differ:

  • Availability Management is proactive, ensuring that services are always available according to agreed standards.

  • Service Continuity Management is more reactive, focusing on planning for, responding to, and recovering from incidents that cause significant service disruption.

Collaboration for Enhanced Service Delivery

Availability Management also needs to collaborate with:

  • Capacity and Performance Management: To ensure that the infrastructure supports the current service availability requirements and is scalable to meet future demands.

  • Information Security Management: To ensure that availability controls do not compromise the security of the services.

Roles & Responsibilities

In ITIL 4, effective availability management requires clear roles and responsibilities across various functions within an organisation. These roles ensure that availability management processes are carried out effectively and are integral to maintaining service quality.

Key Roles

  • Availability Manager: This role is responsible for the overall management of service availability. It involves planning, implementing, and monitoring availability measures to meet the agreed-upon SLAs.

  • Service Owner: This person oversees the lifecycle of specific services and ensures that the availability targets for their service are met. They coordinate with different teams to address availability-related issues.

  • IT Operations Manager: Ensures that the operational activities required to maintain service availability are performed efficiently.

Implementation Advice

Effective implementation of Availability Management requires a strategic approach, considering both the technical and organisational aspects.

Here are some practical guidelines and key metrics to monitor to ensure successful deployment and operation.

Key Metrics

  1. Mean Time Between Failures (MTBF): This measure measures the average time between failures to assess service reliability.

  2. Mean Time to Restore Service (MTRS): This indicator indicates the average time it takes to restore service after a failure, reflecting the efficiency of recovery processes.

  3. Availability Percentage: This primary yet powerful metric represents the proportion of time a service is available about the total time it should be available.

Things to Avoid

  • Over-Engineering Solutions: Designing systems far exceeding availability requirements can lead to unnecessary complexity and increased costs.

  • Neglecting Customer Feedback: Customer input is crucial in assessing the effectiveness of availability management. Ignoring this can lead to misaligned availability targets and dissatisfied users.

  • Isolated Metrics: Avoid relying on single metrics. A combination of metrics should be used to view service availability and performance comprehensively.

Frequently Asked Questions

To further aid the understanding and implementation of Availability Management, here are some commonly asked questions and their answers:

What is the difference between Availability and Reliability?

  • Availability refers to the ability of a service to be usable as expected upon demand.

  • Reliability focuses on the service's ability to perform without failure over a specified period under specified conditions.

How do you balance Availability with Cost?

Balancing availability and cost involves determining the optimal level of availability that meets business needs without excessive investment. This requires analysing business impact, the cost of downtime, and investment in technology and processes that enhance availability.

Can Availability Management be automated?

Certain aspects of Availability Management, such as monitoring tools and incident management systems, can be automated. Automation helps promptly detect and respond to availability issues, thus reducing downtime.

What are the best practices for improving service availability?

Best practices include:

  • Implementing redundancy and failover mechanisms.

  • Regular testing and maintenance of IT infrastructure.

  • Continuous monitoring and real-time analytics to detect and resolve issues promptly.

How is service availability measured in a multi-service environment?

In environments with multiple services, availability is often measured per service or as an aggregate metric. It is essential to define clear availability criteria for each service based on its business impact and integrate monitoring tools that provide visibility across all services.


About the author

Hi, I'm Alan, and have been working within the IT sector for over 30 years.

For the last 15 years, I've focused on IT Governance, Information Security, Projects and Service Management across various styles of organisations and markets.

I hold a degree in Information Systems, ITIL Expert certificate, PRINCE2 Practitioner and CISMP (Information Security Management).


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