Search results
Results From The WOW.Com Content Network
High availability (HA) is a characteristic of a system that aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. [ 1 ] There is now more dependence on these systems as a result of modernization.
Reliability, availability and serviceability (RAS), also known as reliability, availability, and maintainability (RAM), is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. The phrase was originally used by IBM as a term to describe the robustness of their mainframe computers.
For databases reliability, availability, scalability and recoverability (RASR), is an important concept. Atomicity, consistency, isolation (sometimes integrity), durability is a transaction metric. When dealing with safety-critical systems, the acronym reliability, availability, maintainability and safety is frequently used.
Reliability: Ability to perform a specific function and may be given as design reliability or operational reliability Availability : Ability to keep a functioning state in the given environment Maintainability : Ability to be timely and easily maintained (including servicing, inspection and check, repair and/or modification)
In reliability engineering, the term availability has the following meanings: The degree to which a system , subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e. a random, time.
The terms high availability, continuous operation, and continuous availability are generally used to express how available a system is. [3] [4] The following is a definition of each of these terms. High availability refers to the ability to avoid unplanned outages by eliminating single points of failure. This is a measure of the reliability of ...
Availability includes non-operational periods associated with reliability, maintenance, and logistics. This is measured in terms of nines. Five-9's (99.999%) means less than 5 minutes when the system is not operating correctly over the span of one year. Availability is only meaningful for supportable systems.
The design parameters generally include reliability, maintainability of the system. Reliability will be the result of manufacturing of the system where as maintainability is coming from operational, maintenance logistics, inventory management, Prognostic Health Management (PHM) and supply chain design of the services that system require. [1]