Data Flow Diagrams (DFDs) are graphical tools used in software engineering to visualize how data moves through a system. A DFD shows the flow of data between external entities and processes, as well as data storage components. It uses standard symbols like rectangles, circles, and arrows. DFDs are hierarchical, with multiple levels showing increasing detail. A 0-level DFD provides an overview of the entire system as a single bubble, while 1-level and 2-level DFDs decompose this into subprocesses and further detail. Key aspects like inputs, outputs, processes, and data storage are represented. DFDs do not show control flow or logic.

1. DFD:Data Flow
Diagram

3. Introduction
Data Flow Diagrams (DFD) are powerful tools used in
software engineering to visualize the flow of data and
processes within a system. The following are some key
points regarding DFD:
 They provide a clear and concise representation of
how data moves through different components .
 It also gives insight into the inputs and outputs of each
entity and the process itself.
 DFD does not have control flow and no loops or
decision rules are present.
 It is a graphical tool, useful for communicating with
users ,managers and other personnel.
 Data Flow diagrams are very popular because they
help us to visualize the major steps and data.
 There are two types of DFD:
 Logical DFD
 Physical DFD

4. 02
Components:
1. Entities: Entities include source and destination of the
data. Entities are represented by rectangle with their
corresponding names.
2. Process: The tasks performed on the data is known as
process. Process is represented by circle. Somewhere
round edge rectangles are also used to represent process.
3. Data Storage: Data storage includes the database of the
system. It is represented by rectangle with both smaller
sides missing or in other words within two parallel lines.
4. Data Flow: The movement of data in the system is known
as data flow. It is represented with the help of arrow. The
tail of the arrow is source and the head of the arrow is
destination.

6. Symbol ForDFD

7. 04. LEVELS

8. The DFD may be used to perform a system or software at
any level of abstraction. Infact, DFDs may be partitioned
into levels that represent increasing information flow and
functional detail. Levels in DFD are numbered 0, 1, 2 or
beyond. Here, we will see primarily three levels in the data
flow diagram :
 0-level DFD
 1-level DFD
 2-level DFD.
Levels in Data Flow Diagrams (DFD)

9. LEVELS
Itisalso known asfundamental
systemmodel, or context
diagramrepresentsthe entire
softwarerequirement asasingle
bubble withinput and output data
denoted byincoming and
outgoing arrows.Thenthe system
isdecomposed and described asa
DFDwith multiple bubbles.
In1-levelDFD,acontext
diagram is decomposedinto
multiplebubbles/processes.
Inthis level,wehighlightthe
mainobjectivesofthesystem
andbreakdown thehigh-level
processof0-levelDFDinto
subprocesses.
2-levelDFDgoesoneprocess
deeperintoparts of1-level
DFD.Itcanbeused to project
orrecordthe
specific/necessarydetail
about thesystem's
functioning.
0-LEVELDFD 1-LEVEL DFD 2-LEVELDFD

10. 5.BUDGETCONTROLING
Budget controlling system data
diagram is often used as a
preliminary step to create an
overview of the budget without
going into greate detail ,which can
later be elebroated. lt normaly
consist of overall application
dataflow and processes of the
budget process. It contains all of the
userflow and their entities such all
the flow of budget.

11. 06.KPI
In a Data Flow Diagram (DFD), Key Performance Indicators (KPIs)
represent the critical metrics used to evaluate the performance
and effectiveness of a system or process.
KPIs are used to assess the success of a system or
process in achieving its goals and objectives. They provide
a quantifiable and measurable way to track performance
over time and identify areas that require improvement.
Integrating KPIs into a DFD allows stakeholders to understand
how data flows within the system and how specific metrics are
calculated and utilized. This helps in monitoring and optimizing
the performance of the system.

12. Acknowledgment:
I would like to express my heartfelt gratitude to Gitosree maam , for their guidance and
support throughout the research and writing process of this term paper. Their invaluable
insights and constructive feedback have significantly contributed to the quality and depth
of this work. I would also like to thank the academic staff and resources at B.P Poddar
Institute of Technology and Management for providing a conducive environment for
learning and research. Furthermore, I extend my appreciation to my fellow students and
peers who engaged in stimulating discussions on exception handling, fostering an
intellectually stimulating atmosphere.

13. Thank
you