Page 229 - SAD bookflip
P. 229

RULES OF DATA FLOW











              All flow must begin with and end at a processing step.



              because data can't transform on its own with being

               process.



              By using the thumb rule, it is quite easily to identify the


               illegal data flows and correct them in a DFD.




















                                                                                                                  14
   224   225   226   227   228   229   230   231   232   233   234