Performance issues holding your mobile app back? You need to prioritise NFRs
Charis Christopoulos, SVP Network and Communication Providers, EMEA at GlobalLogic, explains the importance of key non-functional requirements (NFRs) in mobile app development
When we dream up new software, our minds are abuzz with thoughts about capabilities and the potential impact on business growth and revenue. We dissect these capabilities into requirements, which then morph into features, user stories, and integrations.
But as we transition from ideation to actual development, our mindset shifts. This change in perspective is crucial—it forces us to focus on aspects of the app that are not immediately visible but are, nonetheless, paramount for performance and user experience.
The importance of NFRs in mobile app development
NFRs are the unsung heroes of software development. They are the benchmarks that ensure the product fulfils its business objectives—be that speed, compatibility, localisation, or capacity.
While functional requirements outline what the app is supposed to do, NFRs dictate the level of performance and user satisfaction it should achieve. They are the invisible threads that weave together a seamless user experience.
System architecture designed around a well-established NFR provides a road map for software architecture, implementation, deployment, and post-production maintenance and updates.
Many known NFRs were defined before the first mobile application was developed, meaning it is vital to contextualise NFRs from a mobile development point of view. Here’s what you need to know.
The most essential NFRs in mobile app development
When designing mobile applications, these are the twelve crucial non-functional requirements you must consider:
Accessibility—is all about making the app user-friendly for everyone, including those with special needs or those using the app under unique conditions, like vision impairment or low light. While mobile apps need to meet numerous accessibility standards, it’s particularly important to include voice commands to control and navigate through the application. To enhance accessibility further, you can incorporate special gestures like double-tapping or long-pressing to perform crucial functions.
Adaptability—for a mobile application to meet all its functional requirements, it must support various screen resolutions, a range of manufacturers, and the maximum possible backward compatibility OS versions. Ensuring the application runs smoothly under low bandwidth conditions is also an adaptability NFR.
Availability—for mobile applications, availability as an NFR means executing functions when the backend API is both online and offline. That way, users can perform operations on-demand but only synchronize once services are back online.
Compliance—primarily revolves around the protection and privacy of user data, with requirements set out and enforced by regulations like HIPAA and GDPR. Once you attain the privacy and security NFR, you usually achieve compliance.
Data integrity—ensures smooth execution, with the expectation that the app will recover and retain data as intended when users change the device, install a new version, or perform operations in offline mode.
Data retention—We expect data to be synchronised with backend services and not stored locally in large amounts on the device. The ‘no data retention’ concept is a key NFR for mobile apps. If you need to keep a lot of data in the device’s local storage, the amount of data should guide you – not how long it’s stored.
Deployment—because deployment mainly happens in stores provided by Android or Apple, the deployment NFR for mobile apps centers on basic specifications, informing users about the new versions and stopping usage if users don’t install mandatory updates.
Efficiency—mobile applications must run efficiently with a low memory footprint and battery consumption, as they have limited capacities, unlike web or backend applications.
Privacy—Privacy NFRs are vital for building users’ trust. Above all else, you should foreground transparency, user consent, restricting third-party sharing, data minimisation, the right to erasure, and retention and deletion policies.
Reporting and monitoring—these NFRs are crucial for support and maintenance. Given the limited access support teams have to mobile devices, you need to build in alternative solutions like Firebase or Countly that capture events and user actions and help analyse usage patterns.
Security—interlinked with privacy, security NFRs must include robust mechanisms that protect users’ data. You must consider first-line defences, including authentication, authorisation, encryption, and obfuscation. You should also look toward secure APIs, error handling, and patches. In certain circumstances, you may need to go above and beyond to include threat modelling, penetration testing, and incident response planning. Security isn’t a once-and-done effort. It requires careful monitoring, regular updates, and patches.
Usability—The small form factor means you can’t overlook this NFR. Users should be able to navigate applications and access core functions easily. Aspects like single-hand operations, a minimum scrolling screen, search functionality, and quick navigation are paramount for UX design.
Mobile app NFR key takeaways
NFRs require a proactive and comprehensive approach from mobile app developers. It begins with thorough planning and analysis to identify those relevant to the project. Secondly, you must set clear and measurable targets for each requirement to ensure the app meets user expectations.
Throughout the development process, it’s vital to consider NFRs at every stage. That means continuously evaluating the app’s performance, security measures, and usability and making necessary adjustments and optimisations to meet the desired requirements. Close collaboration between developers, designers, testers, and stakeholders is crucial to addressing NFRs and ensuring a high-quality mobile app.
Rigorous testing methodologies, such as performance, security, and compatibility, will help you validate the app’s adherence to the defined NFRs. Automated testing tools and frameworks streamline the testing process and identify potential performance bottlenecks, security vulnerabilities, and compatibility issues.
NFRs are not a one-time consideration. As technology develops, user expectations change, and new challenges arise. You must continuously monitor and adapt to emerging trends and innovations to ensure your apps meet evolving NFRs.
Prioritising and integrating NFRs in your development process isn’t a task to be ticked off. It’s a strategy that ensures your team will deliver mobile apps that not only meet functional requirements but also excel in performance, security, usability, compatibility, and scalability. Such apps have a higher chance of success in the highly competitive mobile app market, delighting users and establishing a solid reputation for the development team.
About Charis Christopoulos, SVP Network and Communication Providers, EMEA
Charis Christopoulos joined GlobalLogic in 2018 as Chief Technology Officer EMEA, progressing to Managing Director for the UK and Ireland region in 2023. Since January 2024, he has headed the EMEA Communications and Networks business unit. His responsibilities include business development and go-to-market activities in the EMEA region and driving sales, technical pre-sales, and delivery teams to achieve regional targets.
Before joining GlobalLogic, Charis had a long and distinguished twenty-two-year career at Ericsson. His talent and ambition were evident from the start, as he began as a research scientist at Ericsson's global HQ in Stockholm shortly after earning his PhD in Video Processing & Compression from Vrije Universiteit Brussel (VUB), Belgium. Over the years, his work, which included an impressive 22 patents primarily in media and image processing technologies, was published in more than 40 industry and scientific journals, making a significant impact on the field.
Charis held numerous executive leadership positions at Ericsson, including Vice President and Customer Unit CTO for T-Mobile USA—the third-largest mobile operator in the US—where he was responsible for presales and technology strategy, evolution, and delivery of products and solutions.
About GlobalLogic
GlobalLogic is a leader in digital engineering. We help brands across the globe design and build innovative products, platforms, and digital experiences for the modern world. By integrating experience design, complex engineering, and data expertise—we help our clients imagine what’s possible and accelerate their transition into tomorrow’s digital businesses.
Headquartered in Silicon Valley, GlobalLogic operates design studios and engineering centres around the world, extending our deep expertise to customers in the automotive, communications, financial services, healthcare and life sciences, manufacturing, media and entertainment, semiconductor, and technology industries. GlobalLogic is a Hitachi Group Company operating under Hitachi, Ltd. (TSE: 6501), which contributes to a sustainable society with a higher quality of life by driving innovation through data and technology as the Social Innovation Business.