Within

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 thinki ...

, 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 In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns, adjectives, and verb endings, which form the conjugation of verbs. Suffixes can carr ...

many of the words share. They are usually Architecturally Significant Requirements that require architects' attention.

Quality attributes

Notable quality attributes include: *

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. ...

accountability Accountability, in terms of ethics and governance, is equated with answerability, blameworthiness, liability, and the expectation of account-giving. As in an aspect of governance, it has been central to discussions related to problems in the pub ...

accuracy Accuracy and precision are two measures of '' observational error''. ''Accuracy'' is how close a given set of measurements ( observations or readings) are to their '' true value'', while ''precision'' is how close the measurements are to each o ...

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 d ...

* administrability * affordability *

agility Agility or nimbleness is an ability to change the body's position quickly and requires the integration of isolated movement skills using a combination of balance, coordination, speed, reflexes, strength, and endurance. More specifically, it i ...

* auditability *

autonomy In developmental psychology and moral, political, and bioethical philosophy, autonomy, from , ''autonomos'', from αὐτο- ''auto-'' "self" and νόμος ''nomos'', "law", hence when combined understood to mean "one who gives oneself one' ...

rl*

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 ...

compatibility Compatibility may refer to: Computing * Backward compatibility, in which newer devices can understand data generated by older devices * Compatibility card, an expansion card for hardware emulation of another device * Compatibility layer, compon ...

composability Composability is a system design principle that deals with the inter-relationships of components. A highly composable system provides components that can be selected and assembled in various combinations to satisfy specific user requirements. In i ...

rl*

confidentiality Confidentiality involves a set of rules or a promise usually executed through confidentiality agreements that limits the access or places restrictions on certain types of information. Legal confidentiality By law, lawyers are often required ...

configurability In communications or computer systems, a configuration of a system refers to the arrangement of each of its functional units, according to their nature, number and chief characteristics. Often, configuration pertains to the choice of hardware, soft ...

* correctness *

credibility Credibility comprises the objective and subjective components of the believability of a source or message. Credibility dates back to Aristotle theory of Rhetoric. Aristotle defines rhetoric as the ability to see what is possibly persuasive i ...

customizability Customization may refer to: *Customization (anthropology), the process of cultural appropriation and creation of bespoke design * Customization (international marketing), a country-tailored product strategy *Mass customization, the use of computer ...

* debuggability * degradability * determinability * demonstrability * dependability * deployability *

discoverability Discoverability is the degree to which something, especially a piece of content or information, can be found in a search of a file, database, or other information system. Discoverability is a concern in library and information science, many aspects ...

rl* distributability *

durability Durability is the ability of a physical product to remain functional, without requiring excessive maintenance or repair, when faced with the challenges of normal operation over its design lifetime. There are several measures of durability in us ...

effectiveness Effectiveness is the capability of producing a desired result or the ability to produce desired output. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression. Etymology The ori ...

efficiency Efficiency is the often measurable ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and without ...

* evolvability *

extensibility Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be t ...

failure transparency In a distributed system, failure transparency refers to the extent to which errors and subsequent recoveries of hosts and services within the system are invisible to users and applications. For example, if a server fails, but users are automatica ...

fault-tolerance Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the ...

fidelity Fidelity is the quality of faithfulness or loyalty. Its original meaning regarded duty in a broader sense than the related concept of ''fealty''. Both derive from the Latin word ''fidēlis'', meaning "faithful or loyal". In the City of London fin ...

* flexibility * inspectability * installability *

integrity Integrity is the practice of being honest and showing a consistent and uncompromising adherence to strong moral and ethical principles and values. In ethics, integrity is regarded as the honesty and truthfulness or accuracy of one's actions. In ...

* interchangeability *

interoperability Interoperability is a characteristic of a product or system to work with other products or systems. While the term was initially defined for information technology or systems engineering services to allow for information exchange, a broader defi ...

rl* learnability * localizability *

maintainability In engineering, maintainability is the ease with which a product can be maintained to: * correct defects or their cause, * Repair or replace faulty or worn-out components without having to replace still working parts, * prevent unexpected working ...

* manageability *

mobility Mobility may refer to: Social sciences and humanities * Economic mobility, ability of individuals or families to improve their economic status * Geographic mobility, the measure of how populations and goods move over time * Mobilities, a conte ...

* modifiability *

modularity Broadly speaking, modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a sy ...

observability Observability is a measure of how well internal states of a system can be inferred from knowledge of its external outputs. In control theory, the observability and controllability of a linear system are mathematical duals. The concept of observ ...

* operability *

orthogonality In mathematics, orthogonality is the generalization of the geometric notion of '' perpendicularity''. By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...

* portability * precision *

predictability Predictability is the degree to which a correct prediction or forecast of a system's state can be made, either qualitatively or quantitatively. Predictability and causality Causal determinism has a strong relationship with predictability. Per ...

* process capabilities * producibility * provability * recoverability * redundancy *

relevance Relevance is the concept of one topic being connected to another topic in a way that makes it useful to consider the second topic when considering the first. The concept of relevance is studied in many different fields, including cognitive sc ...

* reliability *

repeatability Repeatability or test–retest reliability is the closeness of the agreement between the results of successive measurements of the same measure, when carried out under the same conditions of measurement. In other words, the measurements are take ...

reproducibility Reproducibility, also known as replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in ...

resilience Resilience, resilient, resiliency, or ''variation'', may refer to: Science Ecology * Ecological resilience, the capacity of an ecosystem to recover from perturbations ** Climate resilience, the ability of systems to recover from climate change * ...

responsiveness Responsiveness as a concept of computer science refers to the specific ability of a system or functional unit to complete assigned tasks within a given time. For example, it would refer to the ability of an artificial intelligence system to unde ...

reusability In computer science and software engineering, reusability is the use of existing ''assets'' in some form within the software product development process; these ''assets'' are products and by-products of the software development life cycle and in ...

rl*

robustness Robustness is the property of being strong and healthy in constitution. When it is transposed into a system, it refers to the ability of tolerating perturbations that might affect the system’s functional body. In the same line ''robustness'' ca ...

safety Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings There are two slightly di ...

scalability Scalability is the property of a system to handle a growing amount of work by adding resources to the system. In an economic context, a scalable business model implies that a company can increase sales given increased resources. For example, a ...

* seamlessness *

self-sustainability Self-sustainability and self-sufficiency are overlapping states of being in which a person or organization needs little or no help from, or interaction with, others. Self-sufficiency entails the self being enough (to fulfill needs), and a self-s ...

* serviceability (a.k.a. supportability) * securability *

simplicity Simplicity is the state or quality of being simple. Something easy to understand or explain seems simple, in contrast to something complicated. Alternatively, as Herbert A. Simon suggests, something is simple or complex depending on the way we ...

stability Stability may refer to: Mathematics *Stability theory, the study of the stability of solutions to differential equations and dynamical systems ** Asymptotic stability ** Linear stability ** Lyapunov stability ** Orbital stability ** Structural sta ...

* standards compliance *

survivability Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts. Ecological Following disruptive forces such as flood, fire, disease, war, or climate change some species of flora, fauna, ...

sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...

* tailorability *

testability Testability is a primary aspect of Science and the Scientific Method and is a property applying to an empirical hypothesis, involves two components: #Falsifiability or defeasibility, which means that counterexamples to the hypothesis are logicall ...

* timeliness *

traceability Traceability is the capability to trace something. In some cases, it is interpreted as the ability to verify the history, location, or application of an item by means of documented recorded identification. Other common definitions include the capab ...

* transparency * ubiquity *

understandability Understanding is a psychological process related to an abstract or physical object, such as a person, situation, or message whereby one is able to use concepts to model that object. Understanding is a relation between the knower and an object ...

* upgradability *

usability Usability can be described as the capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience. In software engineering, usability is the degree to which a sof ...

vulnerability Vulnerability refers to "the quality or state of being exposed to the possibility of being attacked or harmed, either physically or emotionally." A window of vulnerability (WOV) is a time frame within which defensive measures are diminished, com ...

Many of these quality attributes can also be applied to

data quality Data quality refers to the state of qualitative or quantitative pieces of information. There are many definitions of data quality, but data is generally considered high quality if it is "fit for tsintended uses in operations, decision making and ...

Common subsets

* Together, reliability, availability, serviceability, usability and installability, are referred to as RASUI. * Functionality, usability, reliability, performance and supportability are together referred to as

FURPS FURPS is an acronym representing a model for classifying software quality attributes ( functional and non-functional requirements): * Functionality - Capability (Size & Generality of Feature Set), Reusability (Compatibility, Interoperability, ...

in relation to software requirements. *

Agility Agility or nimbleness is an ability to change the body's position quickly and requires the integration of isolated movement skills using a combination of balance, coordination, speed, reflexes, strength, and endurance. More specifically, it i ...

in working software is an aggregation of seven architecturally sensitive attributes: debuggability, extensibility, portability, scalability, securability, testability and understandability. * For databases reliability, availability, scalability and recoverability (RASR), is an important concept. * Atomicity, consistency, isolation (sometimes integrity), durability (

ACID In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

) is a transaction metric. * When dealing with safety-critical systems, the acronym reliability, availability, maintainability and safety ( RAMS) is frequently used. * Dependability is an aggregate of availability, reliability, safety, integrity and maintainability. ** Integrity depends on security and survivability. ** Security is a composite of confidentiality, integrity and availability. Security and dependability are often treated together.

Quality attributes

Common subsets

See also

References

Further reading