In Scrum, the teams pay a lot of attention to functional requirements, the things that specify what a product is able to do. There is, however, another very important one that gets less attention: non-functional requirements (NFRs).
Both SW and NFR are necessary in order to develop software that not just works but works best. Let us bust the myth of how the two are different and learn how to handle NFRs in Scrum.
Functional Requirements: What the System Does
Functional requirements state the most important actions and steps a system should do. These are the “needs” by which users can get what they want. They’re usually simple and user-oriented—easy to identify and rank in a product backlog.
Examples:
- The user is able to login using email and password.
- The system requires an email confirmation after a purchase.
- An admin is able to create or remove user accounts.
In Scrum, they are typically documented as user stories and constitute the majority of work in a sprint.
Non-Functional Requirements: The Way the System Acts
Non-functional requirements describe how the system acts. They are concerned with things such as performance, security, scalability, usability, and maintainability. Although they might not be quite as obvious to users, they contribute a lot to the user experience and system quality as a whole.
Examples:
- The homepage should take less than 2 seconds to load.
- The system should be able to handle 10,000 users at a time.
- All passwords should be securely encrypted.
These are generally more technical and more difficult to measure—but no less critical.
Why Are Non-Functional Requirements Often Ignored?
Scrum teams are often more concerned with functional requirements because they are:
- Easier to picture.
- Bound directly to user stories.
- More open during sprint reviews.
- But neglecting NFRs could lead to:
- Slow application.
- Security compromises.
- System crashing due to heavy traffic.
Thus, even with great features in a product, poor non-functional performance can destroy the user experience.
How to Tackle Non-Functional Requirements in Scrum?
To make sure non-functional requirements are not neglected, Scrum teams will need to treat NFRs as first-class citizens of the backlog. Here’s how:
-
Make NFRs Visible in the Backlog
If NFRs are not documented, they will likely be left behind.
Make them user stories just like all other requirements.
Example:
- As a user, I’d like the homepage to take less than 2 seconds to render so that I have rapid access to content.
- As an admin, I’d like user data encrypted so that security and privacy are maintained.
-
Establish Clear Acceptance Criteria
Establish what success will look like. This avoids confusion and ensures expectations are met.
Example Criteria:
- Performance: Load time < 2 seconds for 1,000 users.
- Security: Data should be encrypted through AES-256.
-
Add NFRs to Definition of Done (DoD)
The simplest way to ensure NFRs are not overlooked is to add them to your Definition of Done.
For instance:
- Every page must load below some limit.
- Every security and scalability test must pass before deployment.
-
Mention NFRs At Sprint Planning
Don’t make NFRs an afterthought. Take them into consideration at sprint planning and backlog refinement.
Ask questions such as:
- Will this feature impact performance?
- Are we adding any security threat?
- How does it affect system load?
Functional vs Non-Functional: Which One Is More Important?
Both are equally important. Functional requirements bring the product to life. Non-functional requirements ensure that it lives well—quick, secure, and stable. To recall one at the expense of the other can lead to disastrous results. Scrum teams need to go out of their way to balance both and add NFRs like any user story. When you’re developing in Scrum, don’t be trapped into merely thinking about what the system does. Think as well how well it does it.
By putting equal emphasis on non-functional requirements and functional ones, you create software that’s not just functional, but also fast, secure, and scalable. And that is the gap between a product that works and one that delights customers.
It is important to understand the distinction between functional and non-functional requirements in order to provide high-quality products. HelloSM, the best training institute for Scrum in Hyderabad, provides the next generation Scrum Masters and Agile professionals with hands-on experience, live demonstrations, and industry-level expertise.
Whether you’re a beginner or must refine your Agile philosophy, our course has you covered to be able to tackle the obvious and not-so-obvious elements of software development. Join HelloSM and take your Scrum journey to new heights with expert education and professional certification.
Frequerntly Asked Questions
- What are functional and non-functional requirements in Scrum?
Functional requirements define what the system does, like user logins or transactions. Non-functional requirements describe how it performs—speed, security, and usability.
- Why are non-functional requirements important?
They ensure the system is efficient, secure, and user-friendly. Ignoring them can lead to technical failures or poor user satisfaction.
- How do you write non-functional requirements in Scrum?
Write them as user stories with measurable acceptance criteria, just like functional ones. Example: “As a user, I want pages to load in under 2 seconds.”
- Can you include non-functional requirements in the Definition of Done?
Yes! Adding NFRs to the DoD ensures they’re addressed in every sprint and not skipped over.
- Are NFRs handled differently in Agile compared to Waterfall?
Yes. In Agile/Scrum, NFRs are treated iteratively and integrated into sprints, rather than being handled upfront as in traditional models like Waterfall.