accuracy and completeness with which users achieve specified goals
Efficiency
resources expended in relation to the accuracy and completeness with which users achieve goals
Satisfaction
Usefulness
degree to which a user is satisfied with their perceived achievement of pragmatic goals, including the results of use and the consequences of use
Trust
degree to which a user or other stakeholder has confidence that a product or system will behave as intended
Pleasure
degree to which a user obtains pleasure from fulfilling their personal needs
Comfort
degree to which the user is satisfied with physical comfort
Freedom from risk
Economic risk mitigation
degree to which a product or system mitigates the potential risk to financial status, efficient operation, commercial property, reputation or other resources in the intended contexts of use
Health and safety risk mitigation
degree to which a product or system mitigates the potential risk to people in the intended contexts of use
Environmental risk mitigation
degree to which a product or system mitigates the potential risk to property or the environment in the intended contexts of use
Context coverage
Context completeness
degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in all the specified contexts of use
Flexibility
degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in contexts beyond those initially specified in the requirements
Product quality
Functional suitability
Functional completeness
degree to which the set of functions covers all the specified tasks and user objectives
Functional correctness
degree to which a product or system provides the correct results with the needed degree of precision
Functional appopriateness
degree to which the functions facilitate the accomplishment of specified tasks and objectives
Performance efficiency
Time behaviour
degree to which the response and processing times and throughput rates of a product or system, when performing its functions, meet requirements
Resource utilization
degree to which the amounts and types of resources used by a product or system, when performing its functions, meet requirements
Capacity
degree to which the maximum limits of a product or system parameter meet requirements
Compatibility
Co-existence
degree to which a product can perform its required functions efficiently while sharing a common environment and resources with other products, without detrimental impact on any other product
Interoperability
degree to which two or more systems, products or components can exchange information and use the information that has been exchanged
Usability
Appropriateness recognizability
degree to which users can recognize whether a product or system is appropriate for their needs
Learnability
degree to which a product or system can be used by specified users to achieve specified goals of learning to use the product or system with effectiveness, efficiency, freedom from risk and satisfaction in a specified context of use
Operability
degree to which a product or system has attributes that make it easy to operate and control
User error protection
degree to which a system protects users against making errors
User interface aesthetics
degree to which a user interface enables pleasing and satisfying interaction for the user
Accessibility
degree to which a product or system can be used by people with the widest range of characteristics and capabilities to achieve a specified goal in a specified context of use
Reliability
Maturity
degree to which a system, product or component meets needs for reliability under normal operation
Availability
degree to which a system, product or component is operational and accessible when required for use
Fault tolerance
degree to which a system, product or component operates as intended despite the presence of hardware or software faults
Recoverability
degree to which, in the event of an interruption or a failure, a product or system can recover the data directly affected and re-establish the desired state of the system
Security
Confidentiality
degree to which a product or system ensures that data are accessible only to those authorized to have access
Integrity
degree to which a system, product or component prevents unauthorized access to, or modification of, computer programs or data
Non-repudiation
degree to which actions or events can be proven to have taken place, so that the events or actions cannot be repudiated later
Authenticity
degree to which the identity of a subject or resource can be proved to be the one claimed
Accountability
degree to which the actions of an entity can be traced uniquely to the entity
Mainainability
Modularity
degree to which a system or computer program is composed of discrete components such that a change to one component has minimal impact on other components
Reusability
degree to which an asset can be used in more than one system, or in building other assets
Analysability
degree of effectiveness and efficiency with which it is possible to assess the impact on a product or system of an intended change to one or more of its parts, or to diagnose a product for deficiencies or causes of failures, or to identify parts to be modified
Modifiability
degree to which a product or system can be effectively and efficiently modified without introducing defects or degrading existing product quality
Testability
degree of effectiveness and efficiency with which test criteria can be established for a system, product or component and tests can be performed to determine whether those criteria have been met
Portability
Adaptability
degree to which a product or system can effectively and efficiently be adapted for different or evolving hardware, software or other operational or usage environments
Installability
degree of effectiveness and efficiency with which a product or system can be successfully installed and/or uninstalled in a specified environment
Replaceability
degree to which a product can replace another specified software product for the same purpose in the same environment
