Requirements come in all shapes and sizes, but not all requirements are created equal. In order to be high-quality, a requirement must exhibit four key attributes: atomicity, unambiguity, testability, and necessity. Let’s take a closer look at each of these qualities.
What are the Requirements?
The requirements of a software project are the functions, features, and constraints that need to be met by the final product. In other words, the requirements define what the software should do, how it should look, and any conditions that must be met for it to be considered successful.
Gathering requirements is essential in order to create a product that meets the needs of the customer or client. It is important to note that requirements can change throughout the course of a project, and so it is crucial to have a mechanism in place to track and manage these changes.
Types of Requirements:
There are broadly two types of requirements:
System Requirements – System requirements can be called the expanded version of the user requirements. System requirements act as the commencement point for any new system design. These requirements are a detailed description of the user requirements the system must satisfy.
User Requirements – User requirement is a combination of functional and non-functional requirements. These user requirements must be designed so that they are easily understandable by users who do not have any technical knowledge. Hence, they must be written in natural language using simple tables, forms, and diagrams. Also, make sure the document does not have details on system design, software, or formal notations.
Functional Vs Non-Functional Requirements:
Functional Requirements, as the name suggests, describe the functions of the system to be designed. It is a description of what the system will be and how it will function to satisfy user needs. They provide a clear description of how the system is supposed to respond to a particular command, the features, and what the users expect.
Non-Functional Requirements explain the limitations and constraints of the system to be designed. These requirements do not have any impact on the functionality of the application. Furthermore, there is a common practice of sub-classifying the non-functional requirements into various categories like:
- User Interface
- Reliability
- Security
- Performance
- Maintenance
- Standards
Sub-classifying the non-functional requirements is a good practice. It helps when creating a checklist of the requirements that are to be met in the system to be designed.
Non-functional requirements are as important as functional requirements are. If functional requirements specify what a system should do, non-functional requirements describe how the system will do it. For example, the new application shall provide us with the final list of all connected users. That is a part of functional requirements. If the requirement says that the system would only work on a Windows and a Linux system, that would be a part of non-functional requirements.
The only difference between the two is that the system can not function without satisfying all the functional requirements. On the other hand, the system will give you the desired outcome even when it does not satisfy the non-functional requirements.
4 Main Attributes of High-Quality Requirements:
As we mentioned in the beginning, there are 4 major attributes of high-quality requirements.
- Atomicity – Requirements should be Atomic, that is, they should be indivisible and capable of being completed in a single iteration.
- Unambiguous – Requirements should be Unambiguous, that is, they should have a single interpretation and not leave any scope for doubt.
- Testable – Requirements should be Testable, that is, they should be able to be verified and validated.
- Necessary – Requirements should be Necessary, that is, they should be essential for the successful completion of the project.
Creating high-quality requirements is essential to the success of any software development project. Requirements that are atomic, unambiguous, testable, and necessary will help ensure that the project is completed on time, within budget, and with the desired outcome.
Conclusion:
Requirements are the foundation of any software development project. They provide a common understanding between customers and developers on what needs to be built. High-quality requirements ensure that everyone involved in the project is working towards the same goal, and help avoid costly rework down the road. If you’re looking for a solution to help you manage your requirements effectively, we invite you to try out our free 30-day trial of Visure Requirements ALM Platform. Our platform helps teams collaborate on requirements, track progress, and ensure quality throughout the entire software development lifecycle. Request a free trial today and see how our platform can help your team deliver high-quality products on time and within budget.
