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Sequence Diagram. What is Sequence Diagram?. Sequence Diagram is a dynamic model of a use case, showing the interaction among classes during a specified time period.
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What is Sequence Diagram? • Sequence Diagram is a dynamic model of a use case, showing the interaction among classes during a specified time period. • Sequence Diagram is used primarily to show the interactions between objects in the sequential order that those interactions occur.
Elements of Sequence Diagram • Classes • A class is identified by a rectangle with the name inside. • Lifeline • A lifeline is identified by a Vertical dashed line. • The lifeline represents the time during which the object above it is able to interact with the other objects in the use case. • Activation Bar • Activation bar is identified by a narrow vertical rectangle that covers the lifeline. • It indicates when an object sends or receives a message
Class Lifeline Activation Elements of Sequence Diagram • Symbol
Elements of Sequence Diagram • Message: • Synchronous message – the caller has to wait for the receiving object to complete execution of the called operation before it can resume execution. • Symbol: • Asynchronous message – The caller can execute immediately after sending the message, it does not has to wait for the recipient to handle the message . • Symbol: