Non-Functional Requirements: Trends, Challenges and Best Practices for 2025

3. Interoperability and Open Standards

In a world where systems must seamlessly integrate across platforms, interoperability has gained prominence. This is particularly crucial for industries like healthcare and finance, where data exchange across systems is vital. Open data standards and format-agnostic APIs enable greater flexibility and reduce vendor lock-in.

4. Scalability for Modern Architectures

The rise of microservices, serverless architectures, and edge computing (the next evolution of cloud computing) has amplified the need for scalability. Scalable systems must handle:

• Increasing user demands without degradation in performance.
• Big data workloads, especially in AI/ML-driven projects.
• Global availability with low latency using content delivery networks (CDNs).

5. AI/ML-Specific NFRs

AI is everywhere these days and with AI and machine learning embedded into more applications, unique non-functional requirements are emerging:

Performance: Optimising models for fast inference times without sacrificing accuracy.

Ethicality: ensuring the data on which the AI service is modelled has been created or sourced in accordance with legislation and/or company policy.

Explainability: Ensuring AI decision-making is transparent and understandable so that the quality of outputs can be tested.

Fairness: Minimising bias in algorithms to avoid inadvertent impact on protected characteristics.

Integrating NFRs into Agile

Box UK employs the Agile methodology for all digital products delivered for clients. You can read more on our website about Box UK’s use of Agile but in summary, Agile demands that NFRs are:

1. Shifted Left

NFRs must be considered early in the development lifecycle to identify potential challenges and risks upfront. Collaborative workshops involving cross-functional teams help prioritise these requirements effectively. Waiting to consider NFRs downstream can result in significant delays and increased costs.

2. Continuously Validated

Testing (automated and manual) ensures NFRs like performance, security, and reliability are tested and met at every stage of development. For example:

• Load testing tools (e.g. K9) to ensure scalability.
• Static and dynamic security analysis tools to address vulnerabilities.

3. Dynamically Refined

As projects evolve, so do the NFRs. Agile processes allow for iterative refinement of requirements, ensuring they adapt to new user needs and technical challenges.

Updated Examples of Non-Functional Requirements

Here are some modern examples of NFRs relevant to current and near future digital projects:

Performance

• Real-time applications (e.g. chat support or live dashboards) must deliver data updates within 100 milliseconds to meet user expectations.
• AI-powered features, like recommendation engines or voice assistants, must provide responses in less than 1 second.

Security

• Applications must support adaptive authentication mechanisms that assess risk dynamically (e.g. based on user behavior).
• Quantum-resistant encryption to prepare for potential threats from advancements in quantum computing.

Sustainability

• Integrate tools to track and report digital carbon footprint as part of sustainability initiatives.  
• AI and big data solutions must be designed with energy-efficient algorithms to align with corporate social responsibility goals.

Privacy

• Implement privacy-enhancing technologies, like differential privacy and homomorphic encryption.
• User data collection must support fine-grained consent, allowing users to specify which data can be shared and with whom.

Ethical AI

• Deploying AI for sensitive use cases (e.g. hiring or lending) will need to comply with anticipated AI accountability and transparency regulations.
• AI systems must include continuous monitoring to detect and mitigate biases as data evolves.

Addressing Modern Challenges in NFRs

Ensuring NFRs are not overlooked can be challenging. Several factors contribute to pressure on Product Owners to deprioritise NFRs in favour of often more tangible deliverables. Awareness of these pressures and an understanding of how to manage them is critical to good project governance and positive project outcomes.

Examples of some of those pressures are:

1. Balancing Speed and Quality

The need for rapid delivery often conflicts with the complexity of providing solutions for NFRs. Organisations can mitigate this by:

• Prioritising critical NFRs based on user needs and business impact. See our previous article for guidance on prioritisation of NFRs.
• Leveraging reusable components and libraries that meet established standards.

2. Technical Debt and Legacy Systems

Maintaining NFRs in legacy systems is a significant challenge. Management strategies include:

• Incremental refactoring to modernise codebases.
• Using middleware to bridge gaps between legacy and modern systems.

3. Evolving Standards and Regulations

Compliance requirements, regardless of industry/sector, change frequently. Mitigation tactics include:

• Using risk logs / traceability matrices to capture key compliance requirements and monitor impact on solution development.
• Carrying out regular audits to ensure requirements backlogs and solutions are mindfully updated enabling continued alignment with new standards.

Conclusion

Non-functional requirements are not just a “nice-to-have”; they are integral to the success of digital projects. By addressing security, scalability, sustainability and other NFRs early and iteratively, teams can build robust, user-centered systems that meet the demands of today and tomorrow.

Looking ahead, emerging technologies like Artificial Intelligence, quantum computing, Web3, and advancements in edge computing will introduce new NFRs. Organisations must remain agile and proactive, leveraging tools like AI-driven monitoring and self-healing systems to address these challenges.

As the digital world continues to evolve, Box UK remains committed to providing insights and expertise to help your projects succeed. If you’d like to discuss how we can support your organisation in defining and implementing effective NFRs, get in touch with us today!