What is requirements engineering?
Requirements engineering is the process of defining, documenting, and maintaining requirements. It involves activities like elicitation, analysis, specification, and verification to ensure software meets stakeholders’ needs. Proper management improves project clarity, reduces errors, and aligns expectations.
As development teams work towards shorter time to market and project goals often change dynamically, software requirements engineering has become a vital element of developing innovative, high-quality solutions. Without effective software requirements management, IT projects are more susceptible to delays, errors, increasing costs and user dissatisfaction. That’s why it’s so important that all development team members – managers, engineers and testers – understand and know how to engineer requirements. Read on to find out how to engineer software requirements and how it supports your software delivery.
Benefits of software requirements engineering
Requirements engineering is a tool for regulating processes in software development life cycles (SDLCs). It’s not only crucial at the beginning of a project, when specifications are usually first created, but throughout all stages as projects often require changes or new specifications while development is in progress. Engineering and managing requirements are key processes to maintain control over a project and ensure coherence across the board. They also enable teams to identify, analyze and manage changes so that a project stays aligned with clients’ expectations. Software requirements engineering practices positively impact different aspects of software development:
Project management
Correctly defined and documented requirements enable team members to establish clear project goals and scope. They also help avoid miscommunication and ensure that all stakeholders are in alignment on their expectations regarding the solution in development. Good requirements management results in better project planning and provides information for more accurate assessments of time and resources needed.
Coding
When working with vague or incomplete specifications, engineers have to rely on assumptions, which may lead to mistakes. Well-defined requirements inform developers about how a system should work. They help developers effectively plan, design and implement software that meets clients’ and users’ expectations. Requirements engineering also detects any contradictions and discrepancies in a solution. With exhaustive information in hand, development teams can design the right system architecture and avoid problems when developing future iterations of a solution.
Testing
Among its many other functions, software testing aims to verify if a system meets specific requirements. Requirements serve as a basis for creating test cases and scenarios to run effective tests. Unclear, incomplete or contradictory requirements make the testers’ job much more difficult. For example, vague acceptance criteria can often result in a misinterpretation of functionality descriptions. However, well-defined requirements enable testers to focus on key system elements and better understand system features and user needs.
Read also: What is IT Project Management?
Best practices for software requirements engineering
When a development team gathers business requirements, a client provides information on the needs their solution should address. Next, these expectations are analyzed from a technical perspective and translated into a system design. Once a solution is developed, the team runs acceptance tests to check whether a solution meets business requirements. Given the impact of specifications on the work of a software development team, it’s crucial to approach requirements engineering methodically and consistently.
First, you shouldn’t rush straight into building a system. Trying to meet unrealistic deadlines may result in sloppy testing and inaccurate technical documentation. Communication issues between project stakeholders (such as developers, testers, project managers and end users) can also result in inadequate specifications. To avoid these problems, don’t cut corners when gathering requirements. To facilitate collaboration, you can use methodologies, like Scrum and Agile, which provide tools to improve team communication through sprints, retrospectives and refinements.
Moreover, you shouldn’t assume requirements are self-evident or obvious. The specification “on paper” may differ from what a client actually had in mind. It’s important to thoroughly analyze requirements and make sure everyone is on the same page. You should also connect all relevant information in your documentation to keep track of dependencies in your software. When implementing system requirements, keep in mind business aspects like user journeys and customer needs to ensure alignment beyond good technical performance.
Finally, insufficient knowledge will usually lead to incomplete requirements. That’s why cross-functional development teams should grow their requirements engineering skills. This knowledge will help them improve their software development processes and efficiently manage changes. Companies planning to boost their software development with the help of external teams should look for software partners with demonstrated expertise in automation testing, quality assurance and business analysis.
Structuring and categorizing the requirements
There are different approaches to categorizing software requirements, depending on how granular or high-level you want to get. But, generally, the main types of software requirements include:
- Functionality
- Performance
- Security
- Reliability
- Utility
- Maintainability
- Availability
- Portability (or transferability)
A well-constructed requirement goes much deeper than just its general goal. Providing accurate and sufficient information enables teams to achieve clarity, facilitate project management and develop quality solutions. Ideally, requirements should include these attributes:
- ID – a unique number that makes it easier to track a requirement at different development stages,
- Name – a one-sentence summary of a requirement,
- Date of creation,
- Detailed description,
- Source – information explaining why a requirement is needed (e.g., existing or legacy software, compliance with local laws or company-specific regulations) or who asked for this feature (e.g., stakeholders, a marketing team that’s already thinking about future users),
- Owner – the person who’s responsible for fulfilling the requirement,
- Risk – helps developers assess the likelihood of successful implementation,
- Priority – enables a team to determine the order of implementing different requirements.
Additionally, it’s a good idea to compile complete data about the stakeholders involved in a project. That means including information such as: their name, role, contact data, availability throughout a project, rank within a project, area of expertise, goals and engagement in a project. This information should be defined at the beginning of a project and be readily available to everyone involved. It will help team members communicate and collaborate effectively with stakeholders, for example, if they need feedback or clarification for a specific requirement. Facilitating contact between a team and stakeholders will also keep everyone engaged and eliminate conflicts or misunderstandings.
Gathering the crucial requirements
The ability to apply the right requirements gathering techniques is essential for the success of a software development project. You shouldn’t rely on just one method of collecting requirements – you’ll achieve the best results by combining different techniques, such as:
- Questionnaires and surveys,
- Collaborative workshops and brainstorming sessions,
- Observing existing software and solutions in development,
- Artifact-based analysis,
- Other supporting activities e.g., mind maps, class-responsibility-collaboration (CRC) cards, use case modeling and prototyping.
For more ideas on eliciting and managing requirements, you may want to consider different methods of approaching these processes. For instance, you can try using the Kano model, a framework to help product development teams determine the priority of different features. It highlights three categories of requirements that a team should focus on. Basic features include functionalities that customers normally expect to find in a solution (for example, the ability to pay via a payment app). If these features are missing or malfunctioning, customers are likely to be dissatisfied. Performance features are functionalities that will increase customer satisfaction and could convince potential users to choose your solutions over your competitors. Finally, excitement features also aim to delight and surprise customers with their innovation and uniqueness. These functionalities can boost user loyalty and elevate a solution’s position in the market.
Mastering all stages of SDLCs leads to exceptional solutions
Software requirements engineering is an essential element of project management, software development and testing. Good requirements management helps clearly define project goals, avoid errors and meet expectations of all stakeholders. It also supports effective project planning and software design. At its core, requirements engineering contributes to the success of software projects, which is why it should be treated as an important part of SDLCs. If you want to learn more about developing solutions with an external engineering team whose expertise results in user-centric software that attracts new customers, fill out this form.
About the authorKamil Jędrzejko
Test Manager
A Test Manager with over 6 years’ experience in the software industry, Kamil has a diverse background in testing, quality assurance and business analysis. His ISTQB and IREB certifications and experience with maritime, mobility, health & safety and government projects enable him to efficiently manage test processes and effectively lead a team of manual and automation testers. An active contributor to Software Mind's QA Guild, he’s a proponent of software development that combines technical excellence with business needs.