How Should A Scrum Team Deal With Non-functional Requirements

How a Scrum Team Should Deal with Non-Functional Requirements

Non-functional requirements (NFRs), often overlooked in the initial stages of a project, are crucial for the success of any software product. They define how the system should perform, rather than what it should do. Ignoring them can lead to a technically perfect product that’s unusable or unappealing to its intended audience. This post outlines how a Scrum team should effectively handle NFRs.

Understanding Non-Functional Requirements

Before diving into implementation, let's clarify what NFRs encompass. They are characteristics that describe the system's performance, security, scalability, and usability, among others. Examples include:

• Performance: Response times, throughput, resource utilization.
• Security: Authentication, authorization, data protection.
• Scalability: Ability to handle increasing load and data volume.
• Usability: Ease of use, intuitive interface, accessibility.
• Reliability: System uptime, error handling, recovery mechanisms.
• Maintainability: Ease of modification, code readability, documentation.

Integrating NFRs into the Scrum Process

NFRs shouldn't be treated as separate entities. They should be woven into the fabric of the Scrum process, influencing every stage.

1. Backlog Refinement: Prioritize and Define

During backlog refinement, the team must thoroughly analyze NFRs. This involves:

• Identifying all relevant NFRs: Don't miss any critical aspects.
• Defining measurable criteria: Instead of vague statements like "fast response time," define specific metrics (e.g., "95th percentile response time under 200ms"). This allows for objective assessment.
• Prioritizing NFRs: Not all NFRs carry equal weight. Prioritize based on business value and risk. Addressing critical security vulnerabilities should take precedence over minor UI enhancements.
• Breaking down NFRs into actionable user stories: NFRs are often complex. Break them down into smaller, manageable user stories that can be tackled within a sprint. For example, instead of a user story simply saying "The system must be secure", it can be broken down to: "As a user, I want strong password requirements to protect my data".

2. Sprint Planning: Allocate Resources and Define Acceptance Criteria

During sprint planning, allocate sufficient time and resources to address the prioritized NFRs. The acceptance criteria for user stories should explicitly incorporate NFRs. For instance, a user story about a login feature should include acceptance criteria related to security and performance.

3. Sprint Execution: Consistent Monitoring and Testing

Throughout the sprint, consistently monitor the system's progress against the defined NFR metrics. This involves:

• Regular performance testing: Conduct load tests, stress tests, and other relevant performance evaluations.
• Security testing: Penetration testing and vulnerability assessments should be incorporated.
• Usability testing: User feedback is crucial for validating the usability of the system.

4. Sprint Review: Demonstrate Compliance

During the sprint review, the team demonstrates that the completed work meets the defined NFR criteria. Metrics and test results should be presented as evidence.

5. Sprint Retrospective: Continuous Improvement

The sprint retrospective is an opportunity to reflect on the process of handling NFRs. Identify areas for improvement and adjust the approach for future sprints.

Tools and Techniques

Several tools and techniques can aid in managing NFRs:

• Checklists: Maintain checklists to ensure all relevant NFRs are considered.
• Test frameworks: Utilize appropriate test frameworks for performance, security, and usability testing.
• Monitoring tools: Employ monitoring tools to track system performance and identify potential issues.

By effectively integrating NFRs into the Scrum process, your team can build high-quality software that meets the needs of its users and stakeholders. Remember, the key is proactive planning, consistent monitoring, and continuous improvement.