Quality characteristics

Deliver value with the right quality at speed. That’s what organizations ask of their IT-teams. To determine the right quality the teams use the quality characteristics. These are a very useful tool to identify various characteristics of quality that are important for the stakeholders of an IT-system.

Functional testing usually takes up most of the effort and time spent on testing. Often however, the non-functional testing gets less attention than it should, because many IT-failures relate to non-functional problems. [more info: functional and non-functional testing]

ISO 25010 quality characteristics for product quality

The quality characteristics and their subcharacteristics for product quality are:

• Functional suitability – The degree to which a product or system provides functions that meet stated and implied needs when used under specified conditions.
  Functional completeness
  Functional correctness
  Functional appropriateness
• Performance efficiency – The performance relative to the amount of resources used under stated condition.
  Time behavior
  Resource utilization
  Capacity
• Compatibility – The degree to which a product, system or component can exchange information with other products, systems or components, and/or perform its required functions, while sharing the same hardware or software environment.
  Co-existence
  Interoperability
• Usability – The degree to which a product or system can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use. Appropriateness recognizability
  Learnability
  Operability
  User error protection
  User interface aesthetics
  Accessibility
• Reliability – The degree to which a system, product or component performs specified functions under specified conditions for a specified period of time.
  Maturity
  Availability
  Fault tolerance
  Recoverability
• Security – The degree to which a product or 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
  Integrity
  Non-repudiation
  Accountability
  Authenticity
• Maintainability – The degree of effectiveness and efficiency with which a product or system can be modified by the intended maintainers.
  Modularity
  Reusability
  Analysability
  Modifiability
  Testability
• Portability – The degree of effectiveness and efficiency with which a system, product or component can be transferred from one hardware, software or other operational or usage environment to another.
  Adaptability
  Installability
  Replaceability

Detailed information about these characteristics and their subcharacteristics can be found in [ISO25010 2011].

ISO25010 quality characteristics for quality in use

The quality characteristics and their subcharacteristics for quality in use are:

• Effectiveness – The accuracy and completeness with which users achieve specified goals. (no subcharacteristics)
• Efficiency – The resources expended in relation to the accuracy and completeness with which users achieve goals. (no subcharacteristics)
• Satisfaction – The degree to which user needs are satisfied when a product or system is used in a specified context of use.
  Usefulness
  Trust
  Pleasure
  Comfort
• Freedom from risk – The degree to which a product or system mitigates the potential risk to economic status, human life, health, or the environment.
  Economic risk mitigation
  Health and safety risk mitigation
  Environmental risk mitigation
• Context coverage – The degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in both specified contexts of use and in contexts beyond those initially explicitly identified.
  Context completeness
  Flexibility

Detailed information about these characteristics and their subcharacteristics can be found in [ISO25010 2011].