Essay Example on Analysis Class Diagrams are the blueprints of a System

What is a Sequence Diagram The sequence diagram is used primarily to show the interactions between objects in the sequential order that those interactions occur It is a great way for the visualisation and validation of various runtime scenarios which can help you predict how a system is going to behave Furthermore it helps the discovery of responsibilities that a class might need to have in the process of modelling a system In systems analysis and design they are considered as one of the most important design level models for modern business application development because they focus on identifying the behaviour of a system which is very important Sequence Diagram for Record New Tour use case There are two actors on this system All the sequence of actions is among them The Clerical assistant selects add tour and sends a message to the system Then the System displays the tour details on screen in response to the Clerical Assistant s message The Clerical assistant enters tour details and saves them System shows display message Assign tour driver if tour leader code is recognized otherwise an error message is displayed If the code is recognized then the Clerical Assistant selects Yes System displays the list of drivers with their detailed information and the Clerical assistant selects a driver using driver code Then he saves that information System displays message Add another driver again A Loop will be executed until the clerical assistant selects add another driver equal to Yes If he selects No then the loop will be terminated Alt block is used where there is a condition and loop block is used to execute some actions until false condition occurs