Quick & Simple Explanation of Non-Functional Requirements and Why They matter?

Summary

Non-functional requirements can be tricky for new business analysts, but understanding them becomes easier by comparing them to functional requirements. While functional requirements define what something does, non-functional ones describe how it does it. Examples include performance, scalability, availability, and security, which focus on system quality beyond just functionality. Non-functional requirements help ensure solutions are user-friendly, reliable, and compliant with regulations, providing clarity and preventing confusion during development. The video explores common non-functional requirements and highlights the importance of making them measurable to avoid ambiguity and ensure success.

Takeaways

• 😀 Non-functional requirements describe *how* a system or product works, as opposed to *what* it does (functional requirements).
• 😀 Non-functional requirements are important for ensuring a product meets quality standards beyond its basic functionality.
• 😀 An example of non-functional requirements is the design of a cup: while functional requirements dictate that it can hold and pour water, non-functional requirements specify that it should be lightweight, safe, and comfortable to hold.
• 😀 Non-functional requirements should be measurable to avoid ambiguity and miscommunication, such as specifying exact weight, pressure tolerance, or circumference for a product.
• 😀 Common non-functional requirements include performance, scalability, availability, reliability, maintainability, serviceability, security, regulatory compliance, environmental impact, and usability.
• 😀 Performance requirements define how fast a system should operate, such as load times or processing speeds.
• 😀 Scalability ensures a system can handle an increase in users or data without performance degradation.
• 😀 Availability refers to how often a system is up and running, such as 24/7 availability or scheduled downtime for maintenance.
• 😀 Usability relates to how easy and intuitive a system or product is for users to operate.
• 😀 Regulatory requirements ensure the product complies with legal standards, including privacy laws, financial regulations, and environmental laws.
• 😀 Non-functional requirements not only target end users (e.g., usability, performance), but also focus on system owners (e.g., maintainability, serviceability) and regulatory bodies (e.g., compliance).

Q & A

What is the main difference between functional and non-functional requirements?

Functional requirements describe what a system or product does (e.g., 'a cup must hold water'), while non-functional requirements describe how the system performs those functions (e.g., 'the cup should be lightweight, non-toxic, and shatterproof').

Why can non-functional requirements be confusing for business analysts?

Non-functional requirements can be confusing because they may seem like they don't define any specific functionality, yet they are critical to the product's overall success. They focus on quality and performance factors rather than specific tasks.

Can you provide an example of how non-functional requirements improve a product design?

In the cup example, functional requirements might specify that the cup must hold water and be drinkable, but non-functional requirements would ensure the cup is practical, like specifying that it should be no heavier than 2 pounds or made from non-toxic materials.

What could happen if non-functional requirements are not clearly defined during development?

Without clear non-functional requirements, developers might create a product that technically meets the functional requirements but is impractical or unsafe. For example, a cup might be designed that holds water but is too heavy or made from harmful materials.

What are some common examples of non-functional requirements mentioned in the video?

Common non-functional requirements include performance (e.g., page load time), scalability (e.g., system handling more users), availability (e.g., 24/7 operation), reliability (e.g., critical system uptime), and security (e.g., data protection).

How do non-functional requirements help prevent misunderstandings between developers and stakeholders?

Non-functional requirements provide clear, measurable standards (e.g., 'must be able to withstand 100 lbs of pressure'), reducing the chances of misinterpretation about what is expected, and ensuring alignment between developers and stakeholders.

Why is it important for non-functional requirements to be measurable?

Measurability ensures that the product meets specific quality standards and can be objectively evaluated. For instance, saying a cup should be 'holdable by a hand' is ambiguous, but specifying a certain circumference makes the requirement clear and testable.

What is the role of regulatory requirements among non-functional requirements?

Regulatory requirements are designed to ensure the system complies with legal and ethical standards, such as privacy laws or environmental regulations, to protect users and the company from legal issues.

How do environmental and usability requirements relate to non-functional requirements?

Environmental requirements consider the impact of the system on the world, ensuring it doesn't cause harm, while usability focuses on how easy and intuitive the system is for end-users, both important for creating a positive user experience and meeting broader sustainability goals.

Can you explain the importance of scalability in non-functional requirements?

Scalability ensures that a system can handle an increase in users or load without breaking down. It's essential for growing applications or businesses, as a solution that works with current traffic may not be able to handle increased demand in the future.