- A quality in use model composed of five characteristics that relate to the outcome of interaction when a product is used in a particular context of use.
- A product quality model composed of eight characteristics that relate to static properties of software and dynamic properties of the computer system.
Quality in use model
Quality in use characteristics and subcharacteristics
- Effectiveness: 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: degree to which user needs are satisfied when a system is used in a specified context of use.
- Usefulness: user is satisfied with their perceived achievement of pragmatic goals.
- Trust: stakeholders has confidence that a product or system will behave as intended.
- Pleasure: user obtains pleasure from fulfilling their personal needs.
- Comfort: user is satisfied with physical comfort.
- Freedom from risk: degree to which a system mitigates the risk to economic status, human life, health, or the environment.
- Economic risk mitigation: system mitigates the potential risk to financial status in the intended contexts of use.
- Health and safety risk mitigation: system mitigates the potential risk to people in the intended contexts of use.
- Environmental risk mitigation: system mitigates the potential risk to property or the environment in the intended contexts of use.
- Context coverage: degree to which a system can be used with effectiveness, efficiency, freedom from risk and satisfaction in specified contexts of use and in contexts beyond those initially explicitly identified.
- Context completeness: system can be used in all the specified contexts of use.
- Flexibility: system can be used in contexts beyond those initially specified in the requirements
Product quality model
Product quality characteristics and subcharacteristics
- Functional suitability: degree to which a system provides functions that meet stated needs when used under specified conditions.
- Functional completeness: degree to which the set of functions covers all the specified tasks and user objectives.
- Functional correctness: system provides the correct results with the needed degree of precision.
- Functional appropriateness: the functions facilitate the accomplishment of specified tasks and objectives.
- Performance efficiency: performance relative to the amount of resources used under stated conditions.
- Time behaviour: response, processing times and throughput rates of a system, when performing its functions, meet requirements.
- Resource utilization: the amounts and types of resources used by a system, when performing its functions, meet requirements.
- Capacity: the maximum limits of a product or system parameter meet requirements.
- Compatibility: degree to which a system can exchange information with systems, and/or perform its required functions, while sharing the same hardware or software environment.
- Co-existence: product can perform its functions efficiently while sharing environment and resources with other products.
- Interoperability: a system can exchange information with other systems and use the information that has been exchanged.
- Usability: degree to which a system can be used with effectiveness, efficiency and satisfaction in a specified context of use.
- Appropriateness recognizability: users can recognize whether a system is appropriate for their needs, even before it is implemented.
- Learnability: system can be used to achieve specified goals of learning to use the system.
- Operability: system has attributes that make it easy to operate and control.
- User error protection: system protects users against making errors.
- User interface aesthetics: user interface enables pleasing and satisfying interaction for the user.
- Accessibility: system can be used by people with the widest range of characteristics and capabilities.
- Reliability: degree to which a system performs specified functions under specified conditions for a specified period of time.
- Maturity: system meets needs for reliability under normal operation.
- Availability: system is operational and accessible when required for use.
- Fault tolerance: system operates as intended despite the presence of hardware or software faults.
- Recoverability: system can recover data affected and re-establish the desired state of the system is case of an interruption or a failure.
- Security: degree to which a system protects information and data so that persons or other products or systems have the degree of data access appropriate to their types and levels of authorization.
- Confidentiality: system ensures that data are accessible only to those authorized to have access.
- Integrity: system prevents unauthorized access to, or modification of, computer programs or data.
- Non-repudiation: actions or events can be proven to have taken place, so that the events or actions cannot be repudiated later.
- Accountability: actions of an entity can be traced uniquely to the entity.
- Authenticity: the identity of a subject or resource can be proved to be the one claimed.
- Maintainability: degree of effectiveness and efficiency with which a system can be modified by the intended maintainers.
- Modularity: system is composed of components such that a change to one component has minimal impact on other components.
- Reusability: an asset can be used in more than one system, or in building other assets.
- Analysability: effectiveness and efficiency with which it is possible to assess the impact of an intended change.
- Modifiability: system can be effectively and efficiently modified without introducing defects or degrading existing product quality.
- Testability: effectiveness and efficiency with which test criteria can be established for a system.
- Portability: degree of effectiveness and efficiency with which a system can be transferred from one hardware, software or other operational or usage environment to another.
- Adaptability: system can effectively and efficiently be adapted for different or evolving hardware, software or usage environments.
- Installability: effectiveness and efficiency with which a system can be successfully installed and/or uninstalled.
- Replaceability: product can be replaced by another specified software product for the same purpose in the same environment.
