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BALANCING EXAMPLE

Show sample of context diagram

The process 0 symbol has 2 input flow and 2 output flow

Process 0 considered as a black box, with no internal detail shown

In next slide, process 0 (the parent DFD) is exploded into the next

level of detail

Now 3 processes, 2 data stores, 4 internal data flows are visible

The both DFD are balanced because the 4 data flows into and out
of process 0 are maintained

DFD also leveled because each internal process is numbered to show

that it is a child of the parent process

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