FURPS+

FURPS+ is a way to categorize software requirements, developed by Hewlett-Packard (HP):

• Functionality
• Usability
• Reliability
• Performance
• Supportability
• • => other requirements and constraints

Functionality

Functionality contains the functional requirements aka. capabilities. It also includes non-functional requirements that apply to the entire system like:

• Audit
• Licensing
• Printing
• Reporting
• Security
  • Confidentiality (e.g. only authorized users have access to the data)
  • Integrity (e.g. data is consistent and correct)
  • Availability (e.g. data is available all the time)
• Debugging
• Scheduling

Usability

Also UX contains the requirements that ensure a understandable and easy to learn and use product. Like:

• Accessibility
• Consistency
• Navigation rules (e.g. it concerns the support of using the keyboard, mouse or keyboard shortcuts)
• Training time (e.g. the training of new users will take 2 days or 8 hours)
• Usability standards (e.g. the usability solution will be in line with company policy/standards)

Reliability

The ability of a product to perform a function (action) under specified conditions for a specified period of time or a specified number of operation. It concerns:

• Availability
• Accuracy
• Recoverability

Performance

The performance of a product contains:

• Capacity (e.g. the system must store 5 TB of data)
• Throughput (e.g. the system must support 100k transactions per minute or the system must support the parallel operation of 200 users)
• Response time (e.g. the system must respond in a maximum of 2 seconds, the maximum login time cannot be longer than 1 second)
• Scalability (e.g. that the system must automatically scale)

Supportability

Supportability defines the ability of the system to be operated during the entire life cycle of the system. It consists of:

• Adaptability
• Auditability
• Configurability
• Installability
• Testability
• Maintainability
• Compatibility
• Localization (e.g. the system supports the Polish and English languages)

+

Other Requirements and constraints like:

• Design & implementation (e.g. regarding the need to use a PostgreSQL relational database)
• Interface (e.g. the SOAP standard will be used for integration between the systems)
• Physical elements (e.g. may relate to the selection of specific servers)
• Legal information (e.g. regarding copyright)