Software Engineering - Old Questions

1. Explain system modeling with suitable example.

6 marks | Asked in 2076

System modeling is the process of developing abstract models of a system, with each model presenting a different view or perspective of that system. It is about representing a system using some kind of graphical notation, such as Unified Modeling Language (UML). Models help the analyst to understand the functionality of the system; they are used to communicate with customers.

Models can explain the system from different perspectives:

  • An external perspective, where we model the context or environment of the system.
  • An interaction perspective, where we model the interactions between a system and its environment, or between the components of a system.
  • structural perspective, where we model the organization of a system or the structure of the data that is processed by the system.
  • behavioral perspective, where we model the dynamic behavior of the system and how it responds to events.

Five types of UML diagrams that are the most useful for system modeling:

  • Activity diagrams, which show the activities involved in a process or in data processing.
  • Use case diagrams, which show the interactions between a system and its environment.
  • Sequence diagrams, which show interactions between actors and the system and between system components.
  • Class diagrams, which show the object classes in the system and the associations between these classes.
  • State diagrams, which show how the system reacts to internal and external events.