Project Report of Electricity Billing System
Page - 30
Dataflow Diagram:
Data flow diagram is the starting point of the design
phase that functionally
decomposes the requirements specification. A DFD consists of a series of bubbles
joined by lines. The bubbles represent data transformation
and the lines represent
data flows in the system. A DFD describes what data flow rather than how they are
processed, so it does not hardware, software and data structure.
A
data-flow diagram
(
DFD
) is a graphical representation of the "flow" of data
through an
information
system
. DFDs can also be used for the
visualization
of
data
processing
(structured design). A
data flow diagram
(DFD) is a significant modeling
technique for analyzing and constructing information processes. DFD literally means
an illustration that explains the course or movement of information in a process. DFD
illustrates this flow of information in a process based on the inputs and outputs. A
DFD can be referred to as a Process Model.
The data flow diagram is a graphical description of a system’s
data and how to
Process transform the data is known as Data Flow Diagram (DFD).
Unlike details flow chart, DFDs don’t supply detail descriptions
of modules that
graphically describe a system’s data and how the data interact with the system. Data
flow diagram number of symbols and the following symbols are of by DeMarco.
process
Data store
Source/sink
Data Flow
DeMarco &
Yourdon
symbols
Gane & Sarson
symbols
