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Data Flow Diagram

I'm supposed to be doing a DFD for a real time system of my choice (I chose a Cash Point (ATM)). So - showing all the inputs to the system, all the processes involved and all the outputs.

I've started it, using the symbols she wanted us to use, eg: Circle for process, Recntangle for Entity. But it's already getting really messy with arrows all over the place, so I'm sure I must be doing it wrong.

Click spoiler for overcrowed DFD:

Spoiler

How am I supposed to be laying it out, so that it doesn't get so overcrowded with arrows all over the place? I've not done one of these diagrams before... :s-smilie:

Thanks.

Reply 1

Dhanoo

Stop using curly arrows. :wink:

Reply 2

Joinedup

Yeah just needs tidying up a bit.

When I was learning these we did them landscape with the processes left to right & the data going up and down.

PS drawing cash will affect the balance & obv there's other stuff like checking the amount can be dispensed using the notes that are left in the machines hoppers - cos you'll get fired if more money comes out of people accounts than your software is actually giving them.

Reply 3

ellabell24

Hi,
Do you use any software to draw DFD diagrams? I will recommend you to try Microsoft Visio 2010 for creating DFD diagrams. It is very easy to use and has great features. Hope this will help you.