G063 - Data flow diagrams

Learning Objectives: By the end of this topic you should be able to: describe, interpret and create data flow diagrams

Data Flow Diagrams show how data moves through a system show the processes that transform inputs into outputs Utilises: external entities represent people, organisations …. processes transforms input data into output data data stores database file, a paper form, folder in a filing cabinet flow of data direction of flow of data in the system

Data Flow Diagrams DFD levels level 0 (L0) = summary of the system does not show processes or data stores detail level 1 (L1) = overview of what is happening within the system represented in the L0 diagram by central process box