Danh mục: Unified Modeling Language

A sequence diagram is an interaction diagram that emphasizes the time-ordering of messages. It depicts the objects and classes involved in the scenario and the sequence of messages exchanged between the objects needed to carry out the functionality of the scenario. Typically, you’ll use one sequence diagram to specify a use case’s main flow, and variations of that diagram to specify a use case’s exceptional flows.

A use case is a list of actions or event steps that typically define the interaction between an actor (called an actor in Unified Modeling Language (UML)) and a system to achieve a goal. Actors can be people or other external systems. In systems engineering, use cases are used at a higher level than in software engineering and usually represent task or stakeholder goals.

A use case diagram is a UML diagram that enables you to model system functions (i.e., goals) and the actors that interact with those functions. You can draw use case diagrams in Visual Paradigm or use the Event Flow Editor to document use case usage scenarios. On this page, you will see how to draw use case diagrams with UML tools.

In the area of software testing, “use case” and “test case” are the most critical and closely interrelated terms, but they are quite different. A use case tells us how a system will behave or perform a given task under given conditions. A test case contains the actual test data, the instruction set of the system, and the expected results of the interaction with the system.

Use case diagrams help stakeholders to understand the nature and scope of the business area or the system under development, thus, use case modeling is generally regarded as an excellent technique for capturing the functional requirements of a system. They can be served as the basis for the estimating, scheduling, and validating effort.