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...
Start/End
Input
Decision
Process
Output

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 33 of the text book...
You will find an example scenario and an activity...
Complete the activity.