Functional Requirements: Requirements include functionalities and services that are needed by the users to meet their need and to achieve their business objectives.
Typical functional requirements are:
- Administrative functions
- Authentication
- Authorization levels
- Audit Tracking
- Business Rules
- Certification Requirements
- External Interfaces
- Historical Data
- Legal or Regulatory Requirements
- Transaction correction, adjustments and cancellations.
Non Functional Requirements: Requirements that specifies criteria that can be used to judge the operation of a system, rather than specific behaviors.
Typical non functional requirements are:
- Availability
- Capacity
- Environmental
- Data integrity
- Interoperability
- Maintainability
- Manageability
- Performance (for eg. response time, throughput)
- Reliability
- Recoverability
- Regulatory
- Serviceability
- Security
- Scalability
- Usability