Data
Flow Diagram (DFD)
Description
A
Data Flow Diagram (DFD) tracks processes and their data paths within the
business or system boundary under investigation. A DFD defines each domain
boundary and illustrates the logical movement and transformation of data within
the defined boundary. The diagram shows 'what' input data enters the domain,
'what' logical processes the domain applies to that data, and 'what' output
data leaves the domain. Essentially, a DFD is a tool for process modelling and
one of the oldest.
Uses
A Data Flow Diagram is useful for establishing
the boundary of the business or system domain (the sphere of analysis activity)
under investigation. It identifies any external entities along with their data
interfaces that interact with the processes of interest. A DFD can be a useful
tool (particularly when used as a top DFD - refer to Context
diagram) for helping secure
stakeholder agreement (sign-off) on the project scope. It is also a useful tool
for breaking down a process into its sub-processes for closer analysis.
Application
A Data Flow Diagram can be modelled early in
the requirements elicitation process of the Analysis phase within the System
Development Life Cycle (SDLC) to define the project scope. A DFD can also be
created throughout the SDLC to investigate an aspect of the system. If
necessary, each process under study within a DFD can be broken down into its
sub-processes on a new DFD to show more details. A sub-process in turn can be
broken down further to reveal its sub-processes on a new DFD, and so on until
sufficient analysis is reached. The activity of drilling down the DFD levels is
called 'functional decomposition' with the resulting new DFD referred to as a
'levelled DFD'. For example, the top level DFD (also known as a Context
diagram) is a level 0 DFD,
level 1 DFD refers to the initial decomposition, level 2 DFD to a second level
decomposition, and so on.
Menurut
artikel yg saya kutip diatas menjelaskan tentang pengertian DFD (Data Flow
Diagram) beserta fungsi dan cara penggunaannya di artikel itu menjelaskan bahwa
DFD pada System Development Life Cycle (SDLC) terdiri dari beberapa level di
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