Sequence diagram is an interaction diagram. Interaction diagrams address the dynamic view of a
system, besides sequence diagram, the other interaction diagram in UML is the Collaboration
diagram. Sequence diagram emphasizes the time ordering of messages between objects in the
system, while collaboration diagram emphasizes the structural organization of the objects that
send and receive messages. Sequence diagrams and collaboration diagrams are isomorphic, and
can be transformed from one into the other. Since either of them contributes to the same extend of
understanding of our system, while sequence diagrams give more ideas of time, which is essential
for real time systems, only the sequence diagrams are given in this report.