Functional vs. Non-functional Requirements Questions and Answers for Viva

Answer-1: Functional requirements define the specific behaviors, features, and functions that the software system must perform, such as login functionality or data processing.

Answer-2: Non-functional requirements describe how the system should behave, focusing on attributes like performance, security, scalability, and usability.

Answer-3: Functional requirements describe what the system does, while non-functional requirements describe how the system performs its tasks.

Answer-4: Examples include user authentication, data entry forms, system integrations, and business logic processing.

Answer-5: Examples include system performance, scalability, security, reliability, availability, and usability.

Answer-6: Non-functional requirements ensure that the system performs efficiently, securely, and reliably, providing a quality user experience and maintaining system integrity.

Answer-7: Functional requirements directly define the system?s capabilities and are used as a basis for design, implementation, and testing.

Answer-8: Non-functional requirements influence the architecture, technology stack, and performance optimization efforts, impacting both design and testing phases.

Answer-9: Both types of requirements are interdependent; functional requirements define system features, while non-functional ones define quality attributes for those features.

Answer-10: Functional requirements are measured by defining specific, verifiable actions or outputs, such as response time, completion of transactions, or correct data processing.

Answer-11: Non-functional requirements are measured through metrics like system uptime, response time, throughput, load capacity, and user satisfaction.

Answer-12: Functional requirements serve as the basis for creating test cases to verify that the system performs all specified functions correctly.

Answer-13: Non-functional requirements define the criteria for performance testing, load testing, security testing, and other quality assurance activities to ensure the system meets its quality standards.

Answer-14: Functional requirements help identify key system components, their interactions, and interfaces, guiding the design of the architecture.

Answer-15: Non-functional requirements guide architectural decisions related to scalability, security, redundancy, and performance optimization, ensuring the system meets its operational needs.

Answer-16: Functional requirements are prioritized based on factors like business needs, user impact, legal compliance, and feasibility within project timelines and resources.

Answer-17: Non-functional requirements are prioritized based on the system's critical attributes, such as response time for real-time systems, or security for sensitive applications.

Answer-18: Ignoring functional requirements can lead to a system that lacks core features, causing system failures, user dissatisfaction, or the inability to meet business objectives.

Answer-19: Failing to address non-functional requirements can lead to poor performance, security vulnerabilities, scalability issues, and poor user experience, potentially leading to system failure.

Answer-20: Challenges include unclear stakeholder expectations, miscommunication, scope creep, and balancing competing demands from different users.

Answer-21: Challenges include ambiguity in defining quality metrics, balancing performance vs. cost, and the difficulty in quantifying some non-functional aspects like usability.

Answer-22: Yes, both functional and non-functional requirements can evolve due to changing business needs, technology advancements, user feedback, or environmental factors.

Answer-23: Completeness can be ensured by using techniques like use cases, user stories, prototyping, and continuous stakeholder engagement to capture all possible scenarios.

Answer-24: Completeness is ensured by addressing all aspects of system performance, security, and scalability, and validating them against known benchmarks and standards.

Answer-25: Functional requirements are documented in a requirements specification document, use case diagrams, flowcharts, and functional specifications.

Answer-26: Non-functional requirements are documented in a performance specification document, including metrics for response times, throughput, scalability, and security requirements.

Answer-27: Functional requirements provide the blueprint for system design by outlining the necessary components, their interactions, and user interface design.

Answer-28: Non-functional requirements influence system design decisions, such as choice of technology stack, database design, and overall system architecture to ensure performance and scalability.

Answer-29: Functional requirements directly affect the scope of the project, influencing time and resource estimates, which in turn affect the overall cost of the software.

Answer-30: Non-functional requirements impact the choice of infrastructure, additional security measures, and performance tuning, influencing the cost of development, testing, and maintenance.

Answer-31: Yes, functional requirements are often prioritized based on business value, while non-functional requirements are prioritized based on system needs like performance or security.

Answer-32: Conflicting functional requirements are resolved through discussions with stakeholders, prioritization based on business needs, and sometimes through compromise or trade-offs.

Answer-33: Conflicting non-functional requirements are handled by analyzing system trade-offs, such as balancing security and performance or deciding on acceptable limits for scalability.

Answer-34: In Agile, functional requirements are continuously refined through user stories, ensuring that each iteration delivers incremental value aligned with customer needs.

Answer-35: Non-functional requirements in Agile ensure that each iteration delivers software that is not only functional but also meets performance, security, and quality standards.

Answer-36: Functional requirements are made testable by specifying clear and measurable criteria, often through detailed use cases and expected outcomes.

Answer-37: Non-functional requirements are tested through performance benchmarks, load testing, security audits, and usability tests based on predefined quality metrics.

Answer-38: Functional requirements affect UX by defining core features that users interact with, ensuring that the system is easy to navigate and delivers the expected functionality.

Answer-39: Non-functional requirements affect UX by ensuring that the system is responsive, reliable, secure, and performs well, providing a smooth and satisfying user experience.

Answer-40: By ensuring that all necessary features and behaviors are correctly implemented, functional requirements help build a reliable system that meets user needs.

Answer-41: Non-functional requirements, such as fault tolerance, availability, and redundancy, contribute to system reliability by ensuring it can handle failures and continue to operate smoothly.

Answer-42: Functional requirements impact performance by specifying the operations the system must perform, which directly influences system resource utilization and execution time.

Answer-43: Non-functional requirements like response time, throughput, and scalability influence the system?s ability to handle load, process requests efficiently, and perform under various conditions.

Answer-44: Functional requirements are validated through techniques like walkthroughs, use case testing, peer reviews, and prototype testing to ensure correctness.

Answer-45: Non-functional requirements are validated through performance testing, load testing, stress testing, and security audits to ensure compliance with specified criteria.

Answer-46: Tools like JIRA, Trello, and IBM Rational DOORS can help in tracking and managing functional requirements throughout the software development lifecycle.

Answer-47: Tools like LoadRunner, JMeter, and SonarQube can help track and measure non-functional aspects like performance, security, and code quality.

Answer-48: Functional requirements scope is managed through clear documentation, change control processes, and regular communication with stakeholders to prevent scope creep.

Answer-49: Non-functional requirements scope is managed by defining acceptable performance thresholds, monitoring during development, and adjusting based on feedback and testing.

Answer-50: Functional and non-functional requirements affect maintenance by guiding updates, ensuring continued performance, security, and compliance with user expectations throughout the system's lifecycle.