32
and process. For example; credit cards
verification
uses
real-time link to bank.
Source: Downloaded from http://en.wikipedia.org/wiki/Data_flow_diagram
Figure 2.7 Data Flow Diagram Symbols
For
more
information
about
the
details
of
DFD
decomposition,
see the next sub-chapters below (Figure 2.8 and Figure 2.9)
will
illustrate
it
in a context diagram, diagram
level
zero, and diagram
level one.
Here
is the detail of DFD which starts with context diagram, diagram zero, and
diagram level one:
2.2.3.1.6
Context Diagram
Context diagram represents all
system under
research
in order to explain the scope of the observation in
a
company.
It
shows
the
interaction
between
the
system
and
outside
entities.
This
context- level
DFD
is
then
 |