Ivar Jacobson introduced use cases in the 1980s to help developers articulate system requirements without drowning in technical jargon or feature overload. He described systems as "black boxes," focusing on their interactions with users and other systems. This shift allowed for clearer capture of requirements, which remains essential in software development today. William Hudson, in a video accompanying the article, explains how Jacobson's concept became widely adopted, eventually integrating into the Unified Modeling Language (UML). Use cases consist of two main components: diagrams and narratives. Diagrams provide a visual overview of actors interacting with the system but lack details on timing or sequence. In contrast, narratives outline the interaction process, including the actors involved, their goals, and the steps taken during the interaction. For example, a use case for reserving a seat online outlines the basic flow of logging in, selecting a seat, and confirming the reservation. Pre- and post-conditions are important elements, defining what needs to be true before and after the interaction. The level of detail in use case narratives should match the design stage. Early in the process, avoid specifics like user interface elements; focus instead on the overall flow. For instance, describe actions in general terms rather than detailing how they are performed through specific interface components. Too much detail too soon can stifle creativity and flexibility, leading to what’s termed “premature design.” The article emphasizes that while use cases provide structure, they should remain adaptable to accommodate evolving user needs and behaviors.