1. G063 - Data flow diagrams

2. Learning Objectives: By the end of this topic you should be able to:
describe, interpret and create data flow diagrams

3. Data Flow Diagrams show how data moves through a system
show the processes that transform inputs into outputs
Utilises:
external entities
represent people, organisations ….
processes
transforms input data into output data
data stores
database file, a paper form, folder in a filing cabinet
flow of data
direction of flow of data in the system

4. Data Flow Diagrams DFD levels level 0 (L0) = summary of the system
does not show processes or data stores detail
level 1 (L1) = overview of what is happening within the system
represented in the L0 diagram by central process box