Understanding the Difference Between Functional and Non-Functional Requirements in Business Analysis
Every business needs to define its requirements before embarking on a new project. It is not just about what the customer wants, but it is also about understanding the customer’s needs and transforming them into a final product that satisfies their expectations. Business requirements are broadly classified into two categories – functional requirements and non-functional requirements. The distinction between these two types of requirements is crucial, as they guide the development team towards creating a product that meets all the client’s expectations. Let’s dig deeper into each of these categories.
Functional Requirements
Functional requirements refer to the features and functionalities of the product that the customer will use to achieve their goals. These requirements define how the system should behave in certain situations and what actions it should undertake. For example, consider the development of an e-commerce website. The functional requirements of such a website would include the essential features such as product listings, shopping cart, login and registration, checkout, and payment gateway integration. Functional requirements are usually specific, detailed, and measurable. They describe what the product does, how it does it, and what the final result should look like.
Non-Functional Requirements
Non-functional requirements refer to architectural, performance, and design attributes of a system that enable it to meet its functional requirements. These requirements are not directly related to what the system does, but they are attributes that support the system’s performance. Examples of non-functional requirements include response time, scalability, usability, and security. These requirements describe the system’s performance and operational characteristics and the constraints under which the software will operate. For example, a non-functional requirement for a website may be that it should load within three seconds on a standard 3G network.
Differences Between Functional and Non-Functional Requirements
While both functional and non-functional requirements are crucial to a project’s success, there are some key differences between them. Functional requirements describe what the system should do, while non-functional requirements describe how the system should perform. Functional requirements usually focus on the end-user, while non-functional requirements focus on the system’s architecture and other technical aspects. Functional requirements are easier to define and verify, while non-functional requirements are more challenging to measure and validate. Finally, functional requirements change less frequently as compared to non-functional requirements.
Examples of Functional and Non-Functional Requirements
To understand the difference between functional and non-functional requirements better, let’s look at some examples. For instance, let’s take an online banking system. The functional requirements of such a system would include features such as account management, transaction processing, and balance enquiry. Non-functional requirements, on the other hand, would include the system’s response time, security requirements, and regulatory compliance. In another example, a smartphone’s functional requirements would include features such as the camera, messaging, and phone calls, while non-functional requirements would include aspects such as battery life, screen resolution, and durability.
Conclusion
In conclusion, understanding the difference between functional and non-functional requirements is critical in business analysis. Both types of requirements play a crucial role in delivering a successful product. Functional requirements focus on what the system should do for the end-user, while non-functional requirements focus on how the system should perform to meet the user’s needs. Careful analysis, discussion, and documentation of both types of requirements help ensure that the final product meets the client’s expectations.
