[attachment=14736]
OUTPATIENT DEPARTMENT INFORMATION SYSTEM DEVELOPMENT
Introduction
UML sequence diagram
UML sequence diagrams are used to represent or model the flow of messages, events and actions between the objects or components of a system. Time is represented in the vertical direction showing the sequence of interactions of the header elements, which are displayed horizontally at the top of the diagram.
Sequence Diagrams are used primarily to design, document and validate the architecture, interfaces and logic of the system by describing the sequence of actions that need to be performed to complete a task or scenario.
Benefits of using UML sequence diagrams
These are some of the main benefits of using UML sequence diagrams.
1. Help you discover architectural, interface and logic problems early. Because they allow you to flesh out details before having to implement anything, sequence diagrams are useful tools to find architectural, interface and logic problems early on in the design process.
2. Collaboration tool. Sequence diagrams are valuable collaboration tools during design meetings because they allow you to discuss the design in concrete terms. You can see the interactions between entities, various proposed state transitions and alternate courses/special cases on paper as you discuss the design.
3. Documentation. Sequence diagrams can be used to document the dynamic view of the system design at various levels of abstraction, which is often difficult to extract from static diagrams or even the complete source code. The diagrams can abstract much of the implementation detail and provide a high level view of system behavior.
Sequence Diagrams:
• Illustrate the objects that participate in a use-case
• Show the messages that pass between objects for a particular use-case over time