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As
said
by
Whitten
[4],
a
decomposition
diagram
is
essentially
a
planning
tool
for
more detailed process models, namely, data flow diagrams. The following rules apply:
Each process
in a decomposition diagram either a parent process, a child process
(of a parent), or both.
A
parent
must
have
2
or
more
children
–
a
single
child
does
not
make
sense
because that would not reveal any additional detail about the system.
In
most decomposition diagramming standards, a child may have only one parent.
Finally, a child of one parent may be the parent of its own children.
2.1.5 Distributed Versus Centralized System
According to Whitten [4], a
distributed system
is one
in which the data, process, and
interface components of an information system are distributed to multiple locations in a
computer network.
Accordingly, the processing workload is distributed across the
network.
Instead,
in
centralized
system is
a
central,
multi-
user
computer
hosts
all
the
DATA, PROCESS, and INTERFACE components of an information system.
Users
interact with the system via terminals (or terminal emulators).
Distributed
system
is
more
complicated
difficult
compare
to
centralized
system.
So,
why distributed system used widely nowadays?
1. Modern business systems are already decentralized and distributed.
2. Distributed
computing
moves
information
and
services
closer
to
the
customers
and users who need them.
3. Distributed
computing
consolidates
the
power
of
personal
computers
across
the
enterprise.
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