Specify what messages should be exchanged between the objects in the sequence diagram.From this description, you can easily figure out the interactions (that should go in the sequence diagram) that would occur between the objects, once the use case is executed. Once you identify the objects, write a detailed description on what the use case does.Before drawing the sequence diagram, it’s necessary to identify the objects or actors that would be involved in the particular use case.Before you start drawing the sequence diagram or decide what interactions should be included in it, you need to draw the use case diagram and ready a comprehensive description of what the particular use case does. Sequence diagrams display the flow of events within one single use case.These diagrams are also called event diagrams or scenario diagrams.

Business professionals and software developers use these diagrams to document an existing process or to understand the requirements for a new system. A sequence diagram is a type of interaction diagram that describes how and in what order a group of objects interact.

Sequence diagram online visual paradigm