Use Case digram overview and importance

A Use Case Diagram is one of the most useful diagrams in UML (Unified Modelling Language) and used by Business Analysts so that Business Analysts will understand and communicate system requirements. The main purpose of a Use Case Diagram is to identify the actors, system functions, and relationships between them. Use Case diagram will provides a high-level view of how users or any external systems interact with an application instead of explaining technical implementation, it mainly focuses on what the system should do from the user's perspective. This makes it easy for both technical and non-technical stakeholders to understand the proposed system. Actor represents a person or organization or external application or device that interacts with the system. Use case represents function that the system provides to an actor. Use Case Diagram also contains system boundary, which defines the application scope. Actors are normally shown outside the boundary and functions inside the boundary belong to the system. This particularly useful for a Business Analyst because it helps clearly identify what is included in the project and what is out of scope. There are several relationships used in Use Case Diagrams. Association shows that actor interacts with a particular use case. Include relationship is used when one use case always requires another use case. Extend relationship is mainly used to add optional functionality to use case occurs under a specific condition. Generalization can be used when one actor or use case is a specialized version of another. Use Case Diagrams are important during requirements elicitation, Requirement analysis, and another major benefit is improved communication. Business Analyst can use the diagram during stakeholder meeting to identify what need from the system for user so that BA identify functional requirements and avoid missing important system capabilities. Sometimes Requirements documents can be lengthy and difficult for business stakeholders to understand. A Use Case Diagram provides a visual representation that can be discussed easily during stakeholder or project related meetings. Business stakeholders can quickly identify whether the diagram correctly represents their activities and needs. Use Case diagram is also useful for development and testing. Developers can be used to identify use cases to understand the required functionality of system. Testers can be use the use cases and their detailed flows to derive test scenarios. Therefore, a Use Case Diagram will provide connection between business requirements, development, and testing activities. After BA has gathered sufficient enough information about their business processes from stakeholder then Use Case Diagram should be created during the requirements analysis phase. It can be updated throughout the project whenever changes in requirement. This diagrams also help with system scope management. By clearly showing the system boundary so the stakeholders can understand which functions are part of the project due to this can help reduce misunderstandings and prevent unnecessary expansion of scope. In Simple term, Use Case Diagram is important Business Analysis tool why because it provides visual representation of who uses the system, what they want to accomplish, & how user interact with the system. For Business Analyst, it is effective way to transform complex requirements into an easy and understandable visual model.