Dependability of an item is the ability to perform as and when required.
NOTE 1: Dependability includes availability, reliability, recoverability, maintainability, and maintenance support performance,
and, in some cases, other characteristics such as durability, safety and security.
NOTE 2: Dependability is used as a collective term for the time-related quality characteristics of an item.
Dependability Management Systems
A management system to direct and control an organization with regard to dependability
NOTE 1: The dependability management system of an organization is part of its overall management system.
NOTE 2: The organizational structure, responsibilities, procedures, processes and resources used for managing dependability are often referred to as dependability programme.
Life Cycle Phases
A definable stage or phase referring to the various time intervals from a product's inception until its ultimate removal from use and disposal.
A product life cycle consists of the following phases:
concept (including definition;
development (including design);
realization (incorporating manufacturing);
utilization (operation and maintenance);
Life Cycle Processes
The activities involved in conducting the processes selectively to fulfil the purpose and outcomes of the life cycle of a product or system. These processes may include agreement processes, enterprise processes, project processes, and technical processes.
Maintainability is the ability of an item under given conditions of use, to be retained in, or restored to, a state to perform
as required, under given conditions of use and maintenance.
NOTE 1: Given conditions would include aspects that affect maintainability, such as: location for maintenance, accessibility,
maintenance procedures and maintenance resources.
Maintenance is the combination of all technical and management actions intended to retain an item in, or restore it to, a state in which it
can perform as required.
NOTE: Management is assumed to include supervision activities.Maintenance support is the provision of resources to maintain an item.
Maintenance support is the provision of resources to maintain an item.
NOTE: Resources include human resources, support equipment, materials and spare parts, maintenance facilities, documentation
and information, and maintenance information systems.
Reliability is the ability of an item to perform as required, without failure, for a given time interval, under given conditions.
NOTE 1: The time interval duration may be expressed in units appropriate to the item concerned, e.g. calendar time, operating cycles,
distance run, etc., and the units should always be clearly stated.
NOTE 2: Given conditions include aspects that affect reliability, such as: mode of operation, stress levels, environmental conditions,
Supportability is the ability of an item to be supported to sustain the required availability with a defined operational profile and given logistic
and maintenance resources
NOTE: Supportability of an item results from the inherent maintainability, combined with factors external to the item that
affect the relative ease of providing the required maintenance and logistic support.