Data Flow Diagrams

9 Mar

data.flowIntroduction.DFD show how data through inputs and outputs is processed by a system. Data flow diagrams are made up of 4 vital components (Processes, External entities, data flows and Data stores.

I went through the notes and they said Dfd’s were easy to understand. I totally disagree. This is how I simplify it.
4 components of dfd.
1. Processes convert incoming data flows to outgoing data flows.
2.External entities are objects outside the system with which the system is in contact with. They are the things giving and receiving the systems inputs and outputs.
3.Data flows are lines, tunnels, pipelines (whatever you want to call them) with which information goes. N.B Every data flow must be labelled with what type of data is flowing through.
4.Data Stores save data within the system. They are sometimes referred to as “files”.

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