Physical DFDs : Extension of Logical DFD to include the physical design of system.

1. Physical DFDs : • Extension of Logical DFD to include the physical design of system. • How logical processes are physically implemented • What technology / person performs a process • logical process spit into multiple physical processes • different technologies • different implementations of the same logical processes e.g Phone Orders, Paper Form orders • Audit / Control processes , handling exceptions e.g: CREDIT MANAGER : MAKE CREDIT DECIISIONS MAKE CREDIT DECISION ( CREDIT MANAGER )

2. Physical Process : e.g Enter Transaction (Logical) Scan member bar code ( Physical ) e.g. SAP : Process Order • Physical Data Stores: • master file, temporary file, audit file • Physical Data Flows: e.g Payment (Logical ) Cash, check or credit card (Physical ) • actual data record or field names • data carrier :e.g Order form 4 Tape bar Code Rental Order Receipt

3. Partitioning a physical DFD into programs • processes performed at different times or by different users • batch versus real time • Automation Boundaries