Functional vs Non Functional Requirements
In this tutorial, we are going to discuss about the Functional vs Non Functional Requirements in System design interview series. In the context of system design interviews, understanding functional vs non functional requirements is key to showcasing your ability to design a system that meets both the specific actions it should perform and how it should perform them.
Requirements analysis is an essential process that enables the success of a system or software project to be assessed. Requirements are generally split into two types: Functional and Non-functional requirements. Functional and non functional requirements are two essential aspects of system requirements that define what a system should do and how it should perform.
Functional Requirements
Functional requirements define what a system should do. They describe the specific behaviors, features, and functions that the system must have to meet user needs.
Examples
- User Authentication: A user authentication system must validate user credentials and provide access levels.
- E-commerce website: An e-commerce website should allow users to browse products, add them to a cart, and complete purchases.
- Data Processing: A report generation system must collect data, process it, and generate timely reports.
- Permissions: Only authorized users should be able to delete records.
Characteristics
- Describe system behavior, interactions, and features.
- Can often be represented in use cases, user stories, or scenarios.
- Specific to user needs and business objectives.
How to Identify
- Ask questions about what the system must accomplish, what the end users need, and what functions are critical to operations.
Importance in Interviews
- Demonstrates Understanding of Core Features: Shows you know what the system needs to do to satisfy its primary objectives.
- Basis for System Design: Functional requirements often form the backbone of your system design.
Non-Functional Requirements
Non-functional requirements define how a system should perform, rather than what tasks it performs. They set the standards for the system’s operational qualities and performance attributes.
Examples
- Scalability: The system should handle growth in users or data.
- Performance: The system should process transactions within a specified time.
- Availability: The system should be up and running a defined percentage of time.
- Security: The system must protect sensitive data and resist unauthorized access.
- Usability: The system should be easy to learn and use within 1 hour for new users.
Characteristics
- Describe the quality attributes, standards, and constraints of the system.
- Include aspects like performance, usability, reliability, security, and maintainability.
- Often impact the user experience and operational efficiency but not necessarily the system’s core functionality.
How to Identify
- Ask questions about expected performance, scalability, availability, and other operational qualities.
Importance in Interviews
- Showcases Depth of Design Knowledge: Demonstrates your understanding of the broader implications of system design.
- Highlights System Robustness and Quality: Reflects how well your system design can meet real-world constraints and user expectations.
Integrating Both in Interviews
- Scenario-Based Discussions: When presented with a scenario, identify both the functional (what the system should do) and non-functional (how the system should do it) requirements.
- Balancing Act: Exhibit your ability to balance both types of requirements, showing that you can design a system that not only meets its functional goals but also performs effectively, securely, and reliably.
Key Differences
Lets discuss about Functional vs Non Functional Requirements main differences.
In System Design Interviews
When you’re in a system design interview, here’s how you can handle Functional vs Non Functional Requirements:
- Clarify Requirements: Start by asking questions to understand both functional and non-functional requirements. Interviewers often leave these vague to see if you’ll probe for more details.
- Prioritize: Not all requirements are equally important. Identify which ones are critical for the system’s success.
- Trade-offs: Discuss trade-offs related to different architectural decisions, especially concerning non-functional requirements. For example, a system highly optimized for read operations might have slower write operations.
- Use Real-World Examples: If you can, relate your points to real-world systems or your past experiences. This shows practical understanding.
- Balance: Ensure you’re not focusing too much on one type of requirement over the other. A well-rounded approach is often necessary.
Remember, in system design interviews, interviewers are often interested in seeing how you think and approach problems, not just your final solution. Demonstrating a clear understanding of both functional and non-functional requirements is key to showing your comprehensive knowledge in system design.
That’s all about the Functional vs Non Functional Requirements. If you have any queries or feedback, please write us at contact@waytoeasylearn.com. Enjoy learning, Enjoy system design interview series..!!