types of non functional requirements, Non-functional requirements (NFRs) define the system’s quality attributes, specifying how the system should behave. They ensure the usability and effectiveness of the entire system, and unlike functional requirements that describe specific behavior or system function, NFRs represent criteria to evaluate system performance.
Here are several types of non-functional requirements:
- Performance Requirements:
- Speed: The response time of the system.
- Throughput: The number of transactions a system can handle per unit time.
- Capacity: The maximum number of users the system can handle simultaneously.
- Scalability Requirements: The system’s ability to grow and manage increased demand effectively.
- Usability Requirements: Concerned with user-friendliness and the user interface design, ensuring that the system is intuitive and accessible.
- Reliability & Availability Requirements:
- Reliability: The system’s ability to function without failure over a specific period.
- Availability: The proportion of time the system is functional and working. It’s often represented as a percentage.
- Security Requirements:
- Authentication: Verifying the user’s identity.
- Authorization: Determining if a user has permission to perform a given action.
- Confidentiality: Ensuring that information is accessible only to those authorized to have access.
- Integrity: Ensuring data’s accuracy and consistency.
- Non-repudiation: Ensuring that completed transactions cannot be denied by a party.
- Maintainability & Modifiability Requirements:
- Maintainability: The ease with which a software system can be modified to correct flaws, improve performance, or adapt to a changing environment.
- Modifiability: The system’s ability to allow for the addition of features or modification of existing features.
- Portability Requirements: The ease with which the system can be transferred from one platform or environment to another.
- Backup and Recovery Requirements: The processes through which the system backs up data and how it recovers data in case of a system crash or failure.
- Interoperability Requirements: The ability of the system to operate and coordinate with other products/systems.
- Compliance Requirements: The need to adhere to standards, regulations, or laws relevant to the system, such as GDPR for data privacy or ADA for accessibility.
- Localization & Internationalization Requirements:
- Localization: Adapting a product to meet the language, cultural, and other requirements of a specific region.
- Internationalization: Designing a product in a way that ensures it can be adapted to various languages and regions without engineering changes.
- Cost Requirements: Constraints and conditions related to budget and ongoing operational costs.
When gathering non-functional requirements, it’s essential to be specific, measurable, and clear to avoid ambiguity. Properly defined NFRs help ensure the product’s success by delivering a satisfactory user experience and meeting stakeholders’ expectations.