DFD_TipsV13.pdf

Data Flow Diagram (DFD) Tips

Processes: VerbsDataflows: NounsData Stores: NounsExternal Entities: Nouns

1) Process’s input & output are different2) Each data store should have at least one data flow in and one data flow out3) Each process should have at least one data flow in and one data flow out4) All inputs and outputs should be labeled5) Processes should have an identifier (Ex., 1.0, 2.0, etc.)

Process Process

Process-to-Process

Process Process

Process-to-Process

Process-to-External Entity

ProcessExternal

Entity

Process-to-External Entity

ProcessExternal

Entity

Data Store

Process-to-Data Store

Process Data Store

Process-to-Data Store

Process

External Entity-to-External Entity

External Entity

External Entity

External Entity-to-External Entity

External Entity

External Entity

Data Store

Data Store-to-Data Store

Data StoreData Store

Data Store-to-Data Store

Data Store

External Entity-to-Data StoreExternal Entity-to-Data Store

External Entity

Data StoreExternal

EntityData Store

External Entity

Data Store

External Entity-to-Data Store

External Entity

Data StoreProcess Process

Process-to-Process

Process-to-External Entity

ProcessExternal

Entity

Data Store

Process-to-Data Store

Process

External Entity-to-External Entity

External Entity

External Entity

Data Store

Data Store-to-Data Store

Data Store

External Entity-to-Data Store

External Entity

Data Store