Flowcharts

1
Flowcharts

• 3.3.1

2
This presentation covers

• What is a Flowchart?
• Why are they used?
• How to draw them.

3
Introduction

• Diagrams are great for helping people understand
  how a system works.
• However, for those who have no idea how to create
  a system (generally the customer!) a more
  simplified method of helping them understand what
  the system does needs to be used.
• Flowcharts are simplified diagrams which show
  basic input, output, decisions and processes.
• Because they are simplified diagrams they can
  only be used to show a generalised overview of
  the system or the functions within it.

4
Understanding the symbols

• You can use any symbols that you like...as long
  as you have a key and stick to it...but these are
  the more common symbols used.
• You can see them in the Shapes option in MS
  Applications...

Input
Start/End
Decision
Output
Process
5
Boiling the kettle example
Start
Yes
Is water boiling?
Turn off power
Add water to kettle
No
No
Heat water
Is it full?
End
Yes
Turn on power
6
Your go...

• Produce a data flow diagram which
• Controls a set of traffic lights over a bridge
  which only allows traffic to go over it in one
  direction at a time.
• Lifts a barrier if it senses a car is stationary
  on its weight pad and also if the driver has
  taken a ticket.

7
Your go again...

• Go to the online text book or to page 38 of the
  text book...
• You will find an example scenario and an
  activity...
• Complete the activity.