2_Chapter 4

Page 1

Use case diagram: Used to structure a 'story' depicting the functional aspects of a system within an organisation.

Actor: Stick figure to represent a individual

Use Case: Representation of a function within the system

System Boundary: Rectangle drawn around all of the use cases, represents the confines of the system. (Include system name)

Associations: Line showing link between a use case and actor (Actor can have more than 1 line)

Includes: Shows the link between use cases

Extends: Shows that the functionallity of a use case contributes the functionality of another use case.

Page 2

Data Flow Diagram: A method of the movement of data through a system

Data flow: Arrow used to represent connect one symbol to another

Entity: Person, agent or company outside the organisation, that provides data to the system or recieves information.

Data Store: Storage location within the organisation

Process: Symbol used to describe any activity that transforms data.

Page 3

Context Diagram: Special type of (DFD), dosen't show any internal process instead focuses on interactions between organisation information system and external entities that supply data or recieve information.