Understanding the Meaning of Software Requirements

Capturing software requirements is essential because it helps ensure that the software being developed will meet the needs and expectations of the users. It is a crucial step in the software development process because it helps define the project's scope and serves as a reference for all stakeholders throughout the development process. Without clear and comprehensive requirements, it is difficult for developers to create software that meets the user's needs, leading to delays, cost overruns, and defective products. Additionally, well-defined requirements can help identify potential issues or conflicts early in the development process, saving time and resources in the long run.

Below is a table that highlights the various types of requirements information that can be captured in a software engineering project.

Term	Definition
Business requirement	A high-level business objective of the organization that builds a product or of a customer who procures it.
Business rule	A policy, guideline, standard, or regulation that defines or constrains some aspect of the business. Not a software requirements in itself, but the origin of several types of software requirements.
Constraint	A restriction that is imposed on the choices available to the developer for the design and construction of a product.
External interface requirement	A description of a behavior that a system will exhibit under specific conditions.
Feature	One or more logically related system capabilities that provide value to a user and are described by a set of functional requirements.
Functional requirement	A description of a behavior that a system will exhibit under specific conditions.
Nonfunctional requirement	A description of a property or characteristic that a system must exhibit or constraint that it must respect.
Quality attribute	A kind of nonfunctional requirement that describes a service or performance characteristic of a product
System requirement	A top-level requirement that contains multiple subsystems, which could be all software or software and hardware
User requirement	A goal or task that specific classes of users must be able to perform with a system, or the desired product attribute