DFD for ATM system

DFD (Data Flow Diagram) of an ATM System consist of two levels of DFD. These levels are Level 0 DFD and Level 1 DFD. Both these levels are used for making the DFD of an ATM system.

1. Level 0 DFD :
   This level is also known as Context Level DFD. At this level, only the interacting inputs and outputs with a system are described. The DFD of this level is shown below:

   

2. Level 1 DFD :
   At this level, more detailed information is given about the processing of the ATM system. The DFD of this level is shown below: