A software development requirement is essentially a specification of what a software system should do or achieve. It outlines the functional and non-functional features and characteristics of the software, including its purpose, behavior, performance, and constraints. A good requirement should be clear, complete, unambiguous, testable, feasible, and relevant to the business and user needs.
One way to evaluate the quality of a software development requirement is to use the acronym SMART, which stands for Specific, Measurable, Achievable, Relevant, and Time-bound. Let’s break down each of these criteria and see how they apply to software requirements.
Specific: A good requirement should be precise and well-defined, leaving no room for misinterpretation or confusion. It should state what the software is supposed to do, how it will do it, and what the expected outcomes are. For example, a requirement like “The software should be easy to use” is vague and subjective, while a requirement like “The software should allow users to register, log in, and submit a form with no more than three clicks” is more specific and objective.
Measurable: A good requirement should be quantifiable or verifiable, meaning that it can be measured or tested against some objective criteria. It should define what success looks like and how it can be evaluated. For example, a requirement like “The software should be fast” is not measurable, while a requirement like “The software should load a page in less than two seconds under normal traffic conditions” is measurable and testable.
Achievable: A good requirement should be feasible and realistic, meaning that it can be implemented within the available resources, time, and budget. It should consider the technical, organizational, and environmental constraints and limitations. For example, a requirement like “The software should support unlimited concurrent users” may not be achievable or cost-effective, while a requirement like “The software should support up to 100 concurrent users with a response time of less than 500 milliseconds” is more achievable and realistic.
Relevant: A good requirement should be aligned with the business and user needs, goals, and expectations. It should address a real problem or opportunity and provide value to the stakeholders. For example, a requirement like “The software should have a purple background” may not be relevant to the user experience or the business objectives, while a requirement like “The software should allow users to filter and sort search results by relevance, date, and popularity” is more relevant and valuable.
Time-bound: A good requirement should have a clear timeline or deadline, meaning that it should be implemented within a certain period or milestone. It should consider the urgency and priority of the requirement and the availability of the resources. For example, a requirement like “The software should support multiple languages” may not have a specific timeline or priority, while a requirement like “The software should be ready for beta testing by the end of the month” is time-bound and urgent.
In addition to the SMART criteria, a good software development requirement should also follow some best practices and standards, such as:
Being consistent with the overall software architecture and design principles
Being traceable and linked to the corresponding test cases and acceptance criteria
Being reviewed and approved by the relevant stakeholders and experts
Being documented and communicated in a clear and accessible format
Being updated and maintained throughout the software development lifecycle
To summarize, a good software development requirement should be specific, measurable, achievable, relevant, time-bound, and aligned with best practices and standards. By following these guidelines, software development teams can ensure that their requirements are of high quality and can lead to the development of software that meets or exceeds the expectations.