ITIL Dictionary of Terms

A - Z Dictionary of terms for ITIL. This is the official Dictionary of terms for ITIL, which is a set of practices for IT Service Management. ITIL® is a registered trade mark of AXELOS Limited. View the Agile Dictionary. Managing Successful Programmes (MSP) Dictionary. Project Office Dictionary (P30). Full PRINCE2 glossary of terms. See also Risk Management Dictionary and Project Management Dictionary.

A - acceptance to availability plan | B - back-out to business unit | C - call to customer-facing service | D - dashboard to driver | E - early life support (ELS) to external service provider | F - facilities management to functional escalation | G - H - gap analysis to hot standby | I - identity to ITIL | J - K - job description to known error record | L - lifecycle to live environment | M - maintainability to monitoring | N - near-shore to notional charging | O - objective to overhead | P - pain value analysis to PRojects IN Controlled Environments (PRINCE2) | Q - qualification to quick win | R - RACI to running costs | S - Sarbanes-Oxley (SOX) to system management | T - tactical to Type III service provider | U - underpinning contract (UC) to utility | V - validation to vulnerability | W - warm standby to workload

M - maintainability to monitoring


(ITIL Service Design) A measure of how quickly and effectively an IT service or other configuration item can be restored to normal working after a failure. Maintainability is often measured and reported as MTRS. Maintainability is also used in the context of software or IT service development to mean ability to be changed or repaired easily.

major incident

(ITIL Service Operation) The highest category of impact for an incident. A major incident results in significant disruption to the business.


An informal measure of how easily and effectively an IT service or other component can be managed.

management information

Information that is used to support decision making by managers. Management information is often generated automatically by tools supporting the various IT service management processes. Management information often includes the values of key performance indicators, such as 'percentage of changes leading to incidents' or 'first-time fix rate'.

management information system (MIS)

(ITIL Service Design) A set of tools, data and information that is used to support a process or function. Examples include the availability management information system and the supplier and contract management information system. See also service knowledge management system.

Management of Risk (M_o_R®)

M_o_R includes all the activities required to identify and control the exposure to risk, which may have an impact on the achievement of an organization's business objectives. See for more details.

management system

The framework of policy, processes, functions, standards, guidelines and tools that ensures an organization or part of an organization can achieve its objectives. This term is also used with a smaller scope to support a specific process or activity – for example, an event management system orrisk management system. See also system.

manual workaround

(ITIL Continual Service Improvement) A workaround that requires manual intervention. Manual workaround is also used as the name of a recovery option in which the business process operates without the use of IT services. This is a temporary measure and is usually combined with another recovery option.

marginal cost

(ITIL Service Strategy) The increase or decrease in the cost of producing one more, or one less, unit of output – for example, the cost of supporting an additional user.

market space

(ITIL Service Strategy) Opportunities that an IT service provider could exploit to meet the business needs of customers. Market spaces identify the possible IT services that an IT service provider may wish to consider delivering.


(ITIL Continual Service Improvement) A measure of the reliability, efficiency and effectiveness of a process, function, organization etc. The most mature processes and functions are formally aligned to business objectives and strategy, and are supported by a framework for continual improvement.

maturity level

A named level in a maturity model, such as the Carnegie Mellon Capability Maturity Model Integration.

mean time between failures (MTBF)

(ITIL Service Design) A metric for measuring and reporting reliability. MTBF is the average time that an IT service or other configuration item can perform its agreed function without interruption. This is measured from when the configuration item starts working, until it next fails.

mean time between service incidents (MTBSI)

(ITIL Service Design) A metric used for measuring and reporting reliability. It is the mean time from when a system or IT service fails, until it next fails. MTBSI is equal to MTBF plus MTRS.

mean time to repair (MTTR)

The average time taken to repair an IT service or other configuration item after a failure. MTTR is measured from when the configuration item fails until it is repaired. MTTR does not include the time required to recover or restore. It is sometimes incorrectly used instead of mean time to restore service.

mean time to restore service (MTRS)

The average time taken to restore an IT service or other configuration item after a failure. MTRS is measured from when the configuration item fails until it is fully restored and delivering its normal functionality. See also maintainability; mean time to repair.


(ITIL Continual Service Improvement) Something that is measured and reported to help manage a process, IT service or activity. See also key performance indicator.


(ITIL Service Design) Software that connects two or more software components or applications. Middleware is usually purchased from a supplier, rather than developed within the IT service provider. See also commercial off the shelf.


A short but complete description of the overall purpose and intentions of an organization. It states what is to be achieved, but not how this should be done. See also vision.


A representation of a system, process, IT service, configuration item etc. that is used to help understand or predict future behaviour.


A technique that is used to predict the future behaviour of a system, process, IT service, configuration item etc. Modelling is commonly used in financial management, capacity management and availability management.

monitor control loop

(ITIL Service Operation) Monitoring the output of a task, process, IT service or other configuration item; comparing this output to a predefined norm; and taking appropriate action based on this comparison.


(ITIL Service Operation) Repeated observation of a configuration item, IT service or process to detect events and to ensure that the current status is known.

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