Hi everyone, I hope someone can assist me with data flow diagrams.

I'm having trouble distinguishing an external entity in my context diagram for a payroll system. Is this the right forum for this type of question?

Anyways here is the situation, I've got to create a DFD for payroll payroll and sales systems of a courier company. Can an external entity of the payroll be an office worker who updates the spreadsheets of jobs, courier info, jobtracking data stores? or is the office worker part of the system?

I understand that the obvious external entities would be the bank, government agencies but yeah I'm struggling getting others.

I've looked at various books, web resources about dfd but am still confused about the whole thing. Any help, email or if someone could point me in the right direction would be great.

Cheers,

newbie

the office worker is part of the system

you're doing fine

Is a data flow diagram anything like a sequence diagram? I must confess that I've never heard about dfds before..

i dunno

i've never heard of sequence diagrams before

Nevermind, google never fails. Sequence diagrams models application level interactions from start to finnish and are UML artefacts. Looks like dfds are targeted at showing the information flow at the db level. (?)