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Ility
In systems engineering and requirements engineering, a non-functional requirement (NFR) is a requirement that specifies criteria that can be used to judge the operation of a system, rather than specific behaviours. They are contrasted with functional requirements that define specific behavior or functions. The plan for implementing ''functional'' requirements is detailed in the system ''design''. The plan for implementing ''non-functional'' requirements is detailed in the system ''architecture'', because they are usually architecturally significant requirements. Definition Broadly, functional requirements define what a system is supposed to ''do'' and non-functional requirements define how a system is supposed to ''be''. Functional requirements are usually in the form of "system shall do ", an individual action or part of the system, perhaps explicitly in the sense of a mathematical function, a black box description input, output, process and control functional model or IPO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accessibility
Accessibility is the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i.e. unassisted) and "indirect access" meaning compatibility with a person's assistive technology (for example, computer screen readers). Accessibility can be viewed as the "ability to access" and benefit from some system or entity. The concept focuses on enabling access for people with disabilities, or enabling access through the use of assistive technology; however, research and development in accessibility brings benefits to everyone. Accessibility is not to be confused with usability, which is the extent to which a product (such as a device, service, or environment) can be used by specified users to achieve specified goals with effectiveness, efficiency, convenience, or satisfaction in a specified context of use. Accessibility is also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of System Quality Attributes
Within systems engineering, quality attributes are realized non-functional requirements used to evaluate the performance of a system. These are sometimes named architecture characteristics, or "ilities" after the suffix many of the words share. They are usually Architecturally Significant Requirements that require architects' attention. Quality attributes Notable quality attributes include: * accessibility * accountability * accuracy * adaptability * administrability * affordability * agility * auditability * autonomy rl* availability * compatibility * composability rl* confidentiality * configurability * correctness * credibility * customizability * debuggability * degradability * determinability * demonstrability * dependability * deployability * discoverability rl* distributability * durability * effectiveness * efficiency * evolvability * extensibility * failure transparency * fault-tolerance * fidelity * flexibility * inspectability * instal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Availability
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 probability that an item will operate satisfactorily at a given point in time when used under stated conditions in an ideal support environment. Normally high availability systems might be specified as 99.98%, 99.999% or 99.9996%. Representation The simplest representation of availability (''A'') is a ratio of the expected value of the uptime of a system to the aggregate of the expected values of up and down time (that results in the "total amont of time" ''C'' of the observation window) : A = \frac = \frac Another equation for availability (''A'') is a ratio of the Mean Time To Failure (MTTF) and Mean Time To Repair (MTTR), or : A = \frac = \frac If we define the status function X(t) as : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ility
In systems engineering and requirements engineering, a non-functional requirement (NFR) is a requirement that specifies criteria that can be used to judge the operation of a system, rather than specific behaviours. They are contrasted with functional requirements that define specific behavior or functions. The plan for implementing ''functional'' requirements is detailed in the system ''design''. The plan for implementing ''non-functional'' requirements is detailed in the system ''architecture'', because they are usually architecturally significant requirements. Definition Broadly, functional requirements define what a system is supposed to ''do'' and non-functional requirements define how a system is supposed to ''be''. Functional requirements are usually in the form of "system shall do ", an individual action or part of the system, perhaps explicitly in the sense of a mathematical function, a black box description input, output, process and control functional model or IPO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Testability
Software testability is the degree to which a software artifact (i.e. a software system, software module, requirements- or design document) supports testing in a given test context. If the testability of the software artifact is high, then finding faults in the system (if it has any) by means of testing is easier. Formally, some systems are testable, and some are not. This classification can be achieved by noticing that, to be testable, for a functionality of the system under test "S", which takes input "I", a computable functional predicate "V" must exists such that V(S,I) is true when S, given input I, produce a valid output, false otherwise. This function "V" is known as the verification function for the system with input I. Many software systems are untestable, or not immediately testable. For example, Google's ReCAPTCHA, without having any metadata about the images is not a testable system. Recaptcha, however, can be immediately tested if for each image shown, there is a tag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systems Engineering
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycles. At its core, systems engineering utilizes systems thinking principles to organize this body of knowledge. The individual outcome of such efforts, an engineered system, can be defined as a combination of components that work in synergy to collectively perform a useful function. Issues such as requirements engineering, reliability, logistics, coordination of different teams, testing and evaluation, maintainability and many other disciplines necessary for successful system design, development, implementation, and ultimate decommission become more difficult when dealing with large or complex projects. Systems engineering deals with work-processes, optimization methods, and risk management tools in such projects. It overlaps technical and human-centered disciplines such as industrial engineering, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptability
Adaptability ( la, adaptō "fit to, adjust") is a feature of a system or of a process. This word has been put to use as a specialised term in different disciplines and in business operations. Word definitions of adaptability as a specialised term differ little from dictionary definitions. According to Andresen and Gronau adaptability in the field of organizational management can in general be seen as an ability to change something or oneself to fit to occurring changes. In ecology, adaptability has been described as the ability to cope with unexpected disturbances in the environment. With respect to business and manufacturing systems and processes, adaptability has come to be seen increasingly as an important factor for their efficiency and economic success. In contrast, adaptability and efficiency are held to be in opposition to each other in biological and ecological systems, requiring a trade-off, since both are important factors in the success of such systems. To determine the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backup
In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is " back up", whereas the noun and adjective form is "backup". Backups can be used to recover data after its loss from data deletion or corruption, or to recover data from an earlier time. Backups provide a simple form of disaster recovery; however not all backup systems are able to reconstitute a computer system or other complex configuration such as a computer cluster, active directory server, or database server. A backup system contains at least one copy of all data considered worth saving. The data storage requirements can be large. An information repository model may be used to provide structure to this storage. There are different types of data storage devices used for copying backups of data that is already in secondary storage onto archi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Configuration Management
Configuration management (CM) is a process for establishing and maintaining consistency of a product's performance, functional, and physical attributes with its requirements, design, and operational information throughout its life. The CM process is widely used by military engineering organizations to manage changes throughout the system lifecycle of complex systems, such as weapon systems, military vehicles, and information systems. Outside the military, the CM process is also used with IT service management as defined by ITIL, and with other domain models in the civil engineering and other industrial engineering segments such as roads, bridges, canals, dams, and buildings. Introduction CM applied over the life cycle of a system provides visibility and control of its performance, functional, and physical attributes. CM verifies that a system performs as intended, and is identified and documented in sufficient detail to support its projected life cycle. The CM process f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Requirement
In product development and process optimization, a requirement is a singular documented physical or functional need that a particular design, product or process aims to satisfy. It is commonly used in a formal sense in engineering design, including for example in systems engineering, software engineering, or enterprise engineering. It is a broad concept that could speak to any necessary (or sometimes desired) function, attribute, capability, characteristic, or quality of a system for it to have value and utility to a customer, organization, internal user, or other stakeholder. Requirements can come with different levels of specificity; for example, a requirement specification or requirement "spec" (often imprecisely referred to as "the" spec/specs, but there are actually different sorts of specifications) refers to an explicit, highly objective/clear (and often quantitative) requirement (or sometimes, ''set'' of requirements) to be satisfied by a material, design, product, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disaster Recovery
Disaster recovery is the process of maintaining or reestablishing vital infrastructure and systems following a natural or human-induced disaster, such as a storm or battle.It employs policies, tools, and procedures. Disaster recovery focuses on the information technology (IT) or technology systems supporting critical business functions as opposed to business continuity. This involves keeping all essential aspects of a business functioning despite significant disruptive events; it can therefore be considered a subset of business continuity. Disaster recovery assumes that the primary site is not immediately recoverable and restores data and services to a secondary site. IT service continuity IT Service Continuity (ITSC) is a subset of business continuity planning (BCP) that focuses on Recovery Point Objective (RPO) and Recovery Time Objective (RTO). It encompasses IT disaster recovery planning and wider IT resilience planning. It also incorporates IT infrastructure and servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Service Level Agreement
A service-level agreement (SLA) is a commitment between a service provider and a customer. Particular aspects of the service – quality, availability, responsibilities – are agreed between the service provider and the service user. The most common component of an SLA is that the services should be provided to the customer as agreed upon in the contract. As an example, Internet service providers and telcos will commonly include service level agreements within the terms of their contracts with customers to define the level(s) of service being sold in plain language terms. In this case, the SLA will typically have a technical definition of ''mean time between failures'' (MTBF), ''mean time to repair'' or '' mean time to recovery'' (MTTR); identifying which party is responsible for reporting faults or paying fees; responsibility for various data rates; throughput; jitter; or similar measurable details. Overview A service-level agreement is an agreement between two or mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
