5.2 Data Flow Diagrams Flashcards
What is a data flow diagram? (DFD)
Visual representation of how data is transferred within a system or organisation
Data flow diagram symbols
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A rectangle:
External entity such as
Customer
Employee
Oblong
A process such as
Calculate pay
Review application
A rectangle with a line going through it (Split into a small and large rectangle)
A data store such as
Staff database
Customer database
An arrow
Data flow
A circle
an external entity
Customer
Employee
A table rectangle
A process
Calculate pay
Review application
Impacts affecting the flow of information which causes delayed or inefficiency within an organisation
Information characteristics
Information is entered incorrectly causing delays
Human error
Information is lost or staff don’t follow protocol
Communication breakdown
Meetings postponed or emails unread
Hardware Failure
Network connection breaking or system failure
Special notice
Check CSNewbs for drawing Level 1 DFD and a Level 0 DFD
