A data flow diagram is a graphic representation of a system or portion of system. It consists of data flows, processes, sources, destinations, and stores – all described through the use of easily understood symbols. An entire system can be described from the viewpoint of the data it processes with only four symbol. At the same time, data flow diagrams are powerful enough to show parallel activities. When standard symbols limit communication, a presentation graph, which uses symbols of people, files, terminals, and documents, can be used to discuss a system with users. Which kind of data flow diagrams would a particular (manufacturing, retail, non-profit) business use, for what purpose and why? Solution Answer:) There are two types of data flow diagrams, namely, i. Physical data flow diagram ii. Logical data flow diagram Physical DFDs are suitable for those businesses which are implementation dependent and has clear definition of what tasks are to be performed and how they are performed. Such DFDs relies on physical characteristics that the business has to offer. Purpose of such DFDs is to keep a close track on what is being done and how things are being done for a particular business because this will ensure proper supervision of the in and outs of the business. Logical DFDs are suitable for those businesses which are implementation independent and solely focuses on the flow of data without any regard to the physical characteristic of the business. These DFDs are required to isolate a particular element/data of a business and track its processing. A logical DFD is required because it is easier to visualize a flow for a single data rather than all the data at the same time. .

1. A data flow diagram is a graphic representation of a system or portion of system. It consists of
data flows, processes, sources, destinations, and stores – all described through the use of easily
understood symbols. An entire system can be described from the viewpoint of the data it
processes with only four symbol. At the same time, data flow diagrams are powerful enough to
show parallel activities. When standard symbols limit communication, a presentation graph,
which uses symbols of people, files, terminals, and documents, can be used to discuss a system
with users. Which kind of data flow diagrams would a particular (manufacturing, retail, non-
profit) business use, for what purpose and why?
Solution
Answer:)
There are two types of data flow diagrams, namely,
i. Physical data flow diagram
ii. Logical data flow diagram
Physical DFDs are suitable for those businesses which are implementation dependent and has
clear definition of what tasks are to be performed and how they are performed. Such DFDs relies
on physical characteristics that the business has to offer. Purpose of such DFDs is to keep a close
track on what is being done and how things are being done for a particular business because this
will ensure proper supervision of the in and outs of the business.
Logical DFDs are suitable for those businesses which are implementation independent and solely
focuses on the flow of data without any regard to the physical characteristic of the business.
These DFDs are required to isolate a particular element/data of a business and track its
processing. A logical DFD is required because it is easier to visualize a flow for a single data
rather than all the data at the same time.