43
2.2.3.1 Context Diagram
According
to Satzinger, Jackson, Burd
7
,
context diagram is a DFD
that
describes
the
most
abstract
view
of
a
system.
All
external
agents
and
all
data
flows
into
and
out
of
the
system
are
shown
in
one
diagram,
with the entire system represented as one process. A context diagram
clearly shows the scope of the system a nd boundary. The system scope
is defined by what is presented within the single process and what is
represented as external agents. External agents that that supply or
receive data from the system are outside the system scope, and
everything
else
is
inside
the
system
scope.
The
context
diagram
does
not usually show data stores because all of the system’s data stores are
considered to be within the system scope (that is part of the internal
implementation of the process that represents the system). Figure 2.4
is
the example of a context diagram.
7
Satzin ger, Jakson, Burd (2004). Systems Analysis and Design in a Changing World. 3rd ed.Boston:
Thomson Course Technology. p 85, 204.
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