DETERMINATION OF DFD
Armed with interview results, tabulated questionnaires, and experience through personal observations, the analyst is ready to describe the current system in narrative form, with a data- flow diagram, or with a system flowchart. Since all organizations have an account payable (AP) system let us be in with such an example using a context DFD. A context DFD defines the system understudy in a general form, showing :
Inputs to AP : Packing slips, invoices, checking account balances, payment notifications.
Outputs from AP, reports to management, cheque to suppliers.
A context DFD does not show any detail but is an overview drawing of the system. It is an excellent diagram to share with management whose interest is general in nature. Context DFDs place a boundary around the system under investigation, saying that this is what will be examined – nothing more and nothing less.