Writing Effective Software Requirements. Part 1 – theory

Writing good requirements for a software application is essential for its successful development.

I am a Client. Why would I care about how requirements are built?

As a client, understanding the requirements and effort estimates for your software development project provides several key benefits:

• Clarity and Alignment: Clear requirements help ensure that all stakeholders, including you and the development team, have a shared understanding of what needs to be built. It minimizes miscommunication and reduces the risk of misunderstandings or missed expectations.
• Scope and Prioritization: Detailed requirements allow you to define the scope of the project more effectively. You can identify the essential features and functionalities required for the initial release or minimum viable product (MVP). This helps in prioritizing development efforts and focusing on delivering the most critical components first.
• Budgeting and Resource Planning: With effort estimates, you can have a better understanding of the development effort required for each feature or requirement. This information is valuable for budgeting purposes, resource allocation, and project planning. It allows you to make informed decisions about the investment needed for the project.
• Realistic Timelines: Knowing the effort estimates helps in setting realistic timelines for project completion. It allows you to have reasonable expectations regarding the project’s timeline, taking into account factors such as development complexity, resource availability, and potential dependencies.
• Risk Mitigation: Understanding the effort estimates helps identify potential risks and challenges early on. If certain features or requirements have higher development effort than anticipated, you can proactively address them by adjusting priorities, allocating more resources, or exploring alternative solutions. This proactive approach helps mitigate risks and ensures smoother project execution.
• Effective Communication with the Development Team: Having clarity about requirements and effort estimates enables better communication with the development team. You can provide more specific guidance and feedback, make informed decisions during the development process, and have meaningful discussions about trade-offs or potential modifications based on the estimated effort.
• Quality Assurance and Testing: Well-defined requirements facilitate effective quality assurance and testing processes. By knowing what is expected, you can plan and execute thorough testing activities to ensure that the software meets the specified requirements. It helps in identifying and resolving issues early, reducing the overall development and maintenance costs.

Understanding the requirements and effort estimates provides you, as a client, with the necessary information to make informed decisions, manage expectations, allocate resources effectively, and ensure a successful software development project that aligns with your goals and requirements.

Methods for describing software requirements

Here are some widely adopted methods for describing software requirements:

• User Stories: User stories are concise, user-centric descriptions of a software feature or functionality. They follow a simple template: “As a [user role], I want [goal] so that [benefit].” User stories emphasize the “who,” “what,” and “why” of a requirement, focusing on the end-user’s perspective. They are often written on index cards or in digital tools like JIRA or Trello.
• Acceptance Criteria: Acceptance criteria define specific conditions or behaviors that must be met for a requirement to be considered successfully implemented. They are typically written as a list of statements that outline the expected functionality, performance, and quality attributes. Acceptance criteria provide clear guidelines for developers and serve as a basis for acceptance testing.
• Wireframes and Mockups: Visual representations, such as wireframes and mockups, help convey the user interface (UI) and interaction design of the software. They provide a tangible representation of the proposed system, allowing stakeholders to visualize the expected layout, navigation, and overall user experience. Tools like Sketch, Figma, or Adobe XD are commonly used for creating wireframes and mockups.
• Prototypes: Prototypes are interactive, functional representations of specific parts or flows of the software. They allow stakeholders to experience and interact with the proposed solution early in the development process. Prototyping tools like InVision, Axure, or Marvel enable the creation of interactive prototypes with minimal coding.
• Use Case Diagrams: Use case diagrams depict the interactions between system actors (users or external systems) and the software system itself. They capture the various use cases or scenarios that describe how the system should behave in response to specific actions or events. Use case diagrams help stakeholders understand the system’s functionality and the actors involved.
• Domain Models: Domain models provide a visual representation of the system’s key concepts, entities, and their relationships. They help stakeholders understand the structure of the problem domain and provide a foundation for designing the software’s data model. Unified Modeling Language (UML) class diagrams are commonly used for domain modeling.
• Behavior-Driven Development (BDD): BDD is a collaborative approach that focuses on defining requirements through scenarios and examples. BDD uses a structured language, such as Gherkin, to describe system behavior from a user’s perspective. Scenarios outline expected interactions and outcomes, promoting a shared understanding among stakeholders, developers, and testers.
• Continuous Refinement and Feedback: Modern methods encourage continuous refinement of requirements throughout the software development process. Regular feedback loops, such as sprint reviews, user testing, and retrospectives, facilitate ongoing collaboration, allowing for the incorporation of new insights, adjustments, and refinements to requirements as the project progresses.

These traditional methods won’t work for me.

My requirements change at a fast pace and I need something more dynamic and more modern. 

More modern methods for describing software requirements focus on challenging traditional approaches and promoting innovative ways of capturing, organizing, and validating requirements. These methods aim to address the limitations of traditional methods and adapt to the changing landscape of software development. Here are a few disruptive methods:

• Design Thinking: Design thinking is a human-centered approach that emphasizes empathy, creativity, and iterative problem-solving. It involves understanding users’ needs, brainstorming ideas, prototyping, and gathering feedback. Design thinking encourages a deep understanding of users and their context, leading to innovative solutions that may go beyond conventional requirements.
• User-Centered Design (UCD): UCD involves actively involving end-users throughout the development process, from requirements gathering to usability testing. It emphasizes iterative feedback and collaboration with users, ensuring that the software meets their needs and expectations. Techniques like user interviews, observation, and usability testing help gather insights and refine requirements based on user feedback.
• Minimum Viable Product (MVP): The MVP approach focuses on delivering a minimal, but fully functional version of the software that meets the core needs of users. By prioritizing essential features, an MVP can be quickly developed and deployed to gather user feedback and validate assumptions. This approach allows for rapid iteration and refinement of requirements based on real-world usage and user feedback.
• Lean Requirements: Inspired by lean principles, lean requirements aim to minimize waste and maximize value by focusing only on the most critical requirements. It emphasizes continuous improvement, prioritization, and iterative feedback. Lean requirements advocate for reducing documentation, streamlining processes, and fostering collaboration between stakeholders and development teams.
• User Story Mapping: User story mapping is a technique that helps visualize and prioritize the user journey through a software system. It involves creating a story map by arranging user stories horizontally in the order of user activities and vertically by their priority. User story mapping provides a holistic view of the product, facilitates feature prioritization, and helps identify gaps or opportunities in the requirements.
• Real Options: Real options is an approach that recognizes the value of delaying decisions until the last responsible moment. It acknowledges that uncertainties and evolving market conditions can impact requirements and decision-making. Real options allow for flexibility and adaptability by deferring commitment, enabling stakeholders to make informed decisions based on the latest information available.
• Continuous Discovery and Validation: Disruptive methods often advocate for continuous discovery and validation of requirements throughout the development process. This involves continuously engaging with users, conducting experiments, gathering feedback, and using data-driven insights to refine and validate requirements. Techniques like A/B testing, analytics, and user feedback loops play a crucial role in this approach.

These disruptive methods challenge the traditional notion of requirements as fixed artifacts and embrace a more flexible, iterative, and user-centric approach. They prioritize collaboration, experimentation, and adaptation to ensure that the software meets the evolving needs of users and the market.

It’s important to note that these methods are not mutually exclusive and can be combined based on the specific needs of the project and the preferences of the development team and stakeholders. The key is to adopt an iterative and collaborative approach that promotes effective communication, shared understanding, and continuous improvement of the requirements.

I need examples to understand what works better for my project

Let’s consider a fictional project of developing an online food delivery platform.

We’ll explore how the requirements would look using three modern methods: Design Thinking, User-Centered Design (UCD), and Minimum Viable Product (MVP).

Design Thinking:

Requirement: As a hungry customer, I want a personalized food recommendation feature that suggests dishes based on my dietary preferences, previous orders, and popular choices in my area. The recommendations should consider factors like vegetarian, gluten-free, and low-sodium options.

In this requirement, the focus is on understanding the user’s needs, preferences, and delivering a personalized experience through advanced recommendation algorithms.

User-Centered Design (UCD):

Requirement: Conduct user interviews and usability testing sessions with a diverse group of customers to gather insights on the user experience. Incorporate user feedback to refine the food ordering process, including intuitive navigation, clear dish descriptions, and a streamlined checkout process.

Here, the requirement emphasizes actively involving users throughout the development process, gathering their feedback, and refining the user experience based on their insights.

Minimum Viable Product (MVP):

Requirement: Develop a basic version of the online food delivery platform that allows customers to browse restaurant menus, select dishes, add them to the cart, and place orders. The platform should include basic features like user registration, payment integration, and order tracking.

In this requirement, the focus is on delivering a functional product with essential features that fulfill the core need of customers, enabling them to order food online.

By comparing these examples, you can see the differences in the focus and outcomes of each approach. Design Thinking emphasizes innovative and personalized features, UCD emphasizes user involvement and feedback, and MVP focuses on delivering a functional product quickly. The choice of which method to use depends on your project’s goals, the level of user involvement desired, and the emphasis on innovation vs. speed to market.

How do I make sure that my specifications are truly effective?

Here are some key considerations to help you write effective requirements:

1. Clearly define the project scope: Determine the boundaries of the software application and identify the features and functionalities it should include. This will help you avoid scope creep and ensure that all stakeholders have a common understanding of what the software should do.
2. Involve stakeholders: Engage with all relevant stakeholders, including end-users, clients, developers, and testers. Understand their needs, expectations, and constraints. This collaboration will enable you to gather diverse perspectives and ensure that the requirements reflect the collective understanding of the project.
3. Use a structured format: Adopt a standardized template or format for documenting requirements. This will help maintain consistency and make it easier for stakeholders to understand and review the requirements. A common approach is to use “User Stories,” “Use Cases,” or “Functional Requirements” format.
4. Be specific and unambiguous: Clearly state what the software should and should not do. Avoid vague or ambiguous language that can lead to misinterpretation. Use precise terminology and define any technical jargon or acronyms to ensure everyone understands the requirements in the same way.
5. Focus on functionality, not implementation: Concentrate on what the software needs to achieve rather than how it should be implemented. Requirements should be technology-agnostic and avoid specifying particular programming languages, frameworks, or platforms. This allows developers flexibility in choosing the most suitable solutions.
6. Consider different perspectives: Address requirements from various angles, including functional, non-functional, and user experience aspects. Functional requirements define the specific features and actions the software should provide, while non-functional requirements cover qualities such as performance, security, scalability, and reliability. User experience requirements focus on usability, accessibility, and user interface design.
7. Prioritize requirements: Identify and prioritize the most critical and essential requirements for the initial release or minimum viable product (MVP). This helps manage resources effectively and ensures that the core functionalities are delivered first. Less critical requirements can be scheduled for future iterations or updates.
8. Make requirements measurable: Whenever possible, use measurable criteria to define requirements. This allows for objective evaluation and verification of whether the software meets the specified requirements. For example, instead of stating “The system should be fast,” quantify it as “The system should respond to a search query within two seconds.”
9. Consider edge cases and exceptions: Think about potential scenarios that might fall outside the normal flow of the software. Identify exceptional cases, error handling, and how the software should behave in unusual situations. This helps improve the robustness and reliability of the application.
10. Document assumptions and constraints: Note any assumptions made during the requirement gathering process, as well as any constraints or limitations that might affect the implementation. This helps provide context to the development team and ensures they are aware of any factors that could impact the software design and functionality.
11. Validate and verify requirements: Regularly review the requirements with stakeholders to ensure they accurately capture their needs. Validate the requirements against the desired outcomes and verify that they align with the overall project objectives. This iterative process helps catch errors, gaps, or inconsistencies early on, saving time and effort in later stages of development.

Remember, writing good requirements is an ongoing collaborative effort. Regular communication and feedback from stakeholders, along with the flexibility to adapt as the project progresses, are crucial for success.

Writing effective software requirements is crucial for successful software development. As a client, understanding requirements offers benefits like clarity, scope definition, budgeting, and risk mitigation. Traditional methods like user stories and use case diagrams are widely used, but modern approaches challenge fixed requirements. Disruptive methods like Design Thinking, UCD, and MVP prioritize flexibility and user-centricity. To ensure effective requirements, define scope, involve stakeholders, use a structured format, be specific, prioritize, make them measurable, consider edge cases, and validate continuously. A collaborative, iterative approach fosters successful software projects.

Part 2: Writing Effective Software Requirements. Part 2 – exemples – Encora