Non functional requirements
Here’s a breakdown of common non-functional requirements (NFRs) in solution architecture, along with explanations and examples:
1. Performance
- Scalability: The ability of the system to handle increasing workloads (users, transactions, data) without significant performance degradation.
- Example: “The system should handle up to 5000 concurrent users with response times under 2 seconds for 95% of transactions.”
- Availability: The proportion of time the system is up and functioning. Often expressed as a percentage.
- Example: “The system should have 99.99% uptime (excluding planned maintenance).”
- Response Time: The time taken for the system to respond to a user request.
- Example: “The webpage should load fully within 3 seconds under normal load.”
2. Security
- Confidentiality: Protecting sensitive data from unauthorized access.
- Example: “All user data must be encrypted at rest and in transit.”
- Integrity: Ensuring data is accurate and hasn’t been tampered with.
- Example: “The system must use mechanisms like digital signatures to prevent unauthorized modification of financial transactions.”
- Authentication: Verifying the identity of users before granting access.
- Example: “The system should implement two-factor authentication for all administrative accounts.”
- Authorization: Defining and enforcing access permissions for different roles/users.
- Example: “Standard users should only be able to view their own data, not modify data of others.”
3. Usability
- Ease of Use: How intuitive and easy the system is to learn and use.
- Example: “A new user should complete a core task within 5 minutes without training.”
- Accessibility: Ensuring the system is usable by people with disabilities.
- Example: “The system should comply with WCAG 2.1 AA accessibility guidelines.”
4. Reliability
- Fault Tolerance: The ability of the system to continue operating even when components fail.
- Example: “The system should have redundant web servers to handle individual server failures.”
- Disaster Recovery: The ability to recover the system and its data after a major outage or disaster.
- Example: “The system should have a data backup and replication strategy with recovery point and time objectives (RPO/RTO) of less than 4 hours.”
5. Maintainability
- Modifiability: How easy it is to make changes to the system.
- Example: “Adding a new feature should take less than two developer weeks.”
- Testability: How easy it is to test changes to the system.
- Example: “The system should have unit tests covering 80% of the codebase.”
6. Other Considerations
- Operational Costs: The ongoing costs of maintaining and running the system.
- Compliance: Adherence to laws, regulations, and industry standards.
- Portability: The ability to move the system to different environments (e.g., different cloud providers).
- Supportability: The ease of troubleshooting and providing user support.
Important Notes:
- The importance and specific metrics for NFRs vary wildly between projects.
- NFRs should be defined early on and have measurable targets so they can be considered throughout the design and implementation of the system.
Let me know if you want a deeper dive into a specific category or would like examples tailored to a certain type of solution!