1. Data Flow Diagrams © Dolinski 2007

2. What are they? Data flow diagrams show us how data moves through a system. It is a diagram which looks at all the main aspects of a system and breaks them down into stages.

3. Example Booking a ticket online for a concert involves lots of stages. You can use a DFD to help you understand the stages of this booking.

4. Symbols Shows us choiceShows us how data is used. Shows a processShows flow of data Data that is flowing. E.g. Results of database search returned

5. Online shopper Is product available? Enter product details into search box Product Database Search database Results returned NO. Inform user YES. Display product on screen Add to basket? NO. Go back to start. Finished Shopping? YES. NO. Go back to start. Yes. Go to checkout.

6. Things that could have been included For your DFD you must make sure that you include everything. That was a simple example. It could also have the following: –Receipts –Delivery confirmation –Order tracking

7. What you need to do Create a DFD that shows how data flows through your system during a particular event e.g. LegoLand –How people can book tickets Argos –How people can order products H&M –How people can buy clothes. You may need to carry out some research into all the possible methods for doing these things.

8. TOP TIPS Make sure you explain what data is being passed. Make sure your DFD is neat and that lines to not cross each other. Make sure your arrow heads are pointing the right direction Remember that data should go in full circle. –If a customer orders a product make sure you show the product goes back to the user.