Which technique is commonly used for visualizing requirements?

Use cases are a highly effective technique for visualizing requirements as they provide a structured way to illustrate how users will interact with a system to achieve specific goals. By focusing on user interactions, use cases help in capturing functional requirements in a straightforward manner that both stakeholders and developers can understand.

They detail the various scenarios in which actors (users or other systems) engage with the system, emphasizing the intended behavior of the system in response to various inputs. This visualization not only aids in clearly defining the requirements but also facilitates communication among team members and stakeholders, ensuring that everyone has a shared understanding of the desired outcomes and interactions.

Other techniques listed might assist in documenting requirements, but they do not offer the same clarity of user interaction and scenario-based visualization that use cases provide. Functional specifications detail the specific functions of a system but may not clearly portray user interactions. Data flow diagrams focus on the flow of data within a system rather than user interactions, and project timelines pertain more to scheduling and project management rather than requirement visualization.