FURPS (Functionality, usability, reliability, performance, supportability) is a model for classifying software quality attributes (functional and non-functional requirements):
Model Functionality - capability (size and generality of feature set), reusability (compatibility, interoperability, portability), security (safety and exploitability) Usability (UX) - human factors, aesthetics, consistency, documentation, responsiveness Reliability - availability (failure frequency (robustness/durability/resilience), failure extent and time-length (recoverability/survivability)), predictability (stability), accuracy (frequency/severity of error) Performance - speed, efficiency, resource consumption (power, ram, cache, etc.), throughput, capacity, scalability Supportability (serviceability, maintainability, sustainability, repair speed) - testability, flexibility (modifiability, configurability, adaptability, extensibility, modularity), installability, localizability
The model, developed at Hewlett-Packard was first publicly elaborated by Grady and Caswell. FURPS+ is now widely used in the software industry. The + was later added to the model after various campaigns at HP to extend the acronym to emphasize various attributes, such as Design Requirements, Implementation Requirements, Interface Requirements and Physical Requirements.
See also Types of requirements Expanded list of types of requirements
References
Further reading
External links IBM on Furps+