Use case diagram and importance

Use Case Diagram is the high level diagram. It is designed to explain how external interfaces (end users, databases) are interacting with the system.The main purpose is to identify the requirement. It is modeled from the end user perspective. It's actor specific. It represents the individual features of the system. Use Case Diagram focus on capturing the core functions of the system, avoiding extraneous details.UCD represents only positive flows. It does not represent negative flows or sequence of steps. In UCD, we model functional requirements not technical requirements. After the system is developed how it will be used, we will model it in a use case diagram. The actors will be interacting with the system through distant business functionalities called use cases. The use case is represented in ellipse (oval) shape symbols. In Use Case Diagrams we have 4 elements: a. Primary Actors : Initiates the action with the system. They will be on the left side of the system boundary Secondary Actors: These actors support the system with some information. They will be on the right side of the system boundary. All reusable actors should be placed on the right side of the system boundary. b. System Boundary: It means front end, back end all together ie) screens, third party plugins, database etc. All put together is a system boundary. c. Association: The straight lines which are drawn between actors and use cases are relationships which are called binary associations. It’s the relationship between actors and the use cases Essential Use Case: It should make sense and completeness to the end user. An essential use case supports another essential use case. Supporting Use Case: It should make sense and supports essential use cases. Supporting use cases can support another supporting use case. D. Generalization: The child use cases inherit everything from the parent but can also have their own extra details. Whatever is written in the parent use case (steps, rules) is automatically applied for the child use case also. The child use case does not need to repeat those steps. The Use Case Diagram offers many benefits throughout the system development process. these are some key advantages of using Use Case Diagrams: Use Case Diagrams offer a clear visual representation of a system’s functions and its interactions with external users. This representation helps stakeholders, including those without technical expertise, in grasping the system’s overall behavior. They establish a shared language for articulating system requirements, ensuring that all team members have a common understanding. Use Case Diagram illustrate the different ways users engage with the system, contributing to a thorough comprehension of its functionalities. In the design phase, Use Case Diagrams help outline how users (actors) will interact with the system. They support the planning of user interfaces and aid in structuring system functionalities. For use case diagrams, MS Visio/draw.io provides a user-friendly interface that allows to easily drag and drop actors, use cases, and system boundaries onto the canvas. It offers a variety of UML elements and enables me to represent relationships such as "include" and "extend" with just a few clicks. The tool's interactivity and customizable templates make it straightforward to map out the system's functional requirements and user interactions.