WELCOME

DATA FLOW DIAGRAMS

Presented by:-Vishal Gupta

Gaurav JaiswalAshish TulsianZishan Hayat

Deepak PandeyBasant kumar

DATA FLOW DIAGRAM

A graphical representation of the flow of data.

To visualize the data processing.

Also known as bubble chart.

SYMBOLS USED

Example:-

ADVANTAGES

1. It tracks any information entering or leaving the system.

2. It is a simplified but powerful technique.

3. It depicts how changes to information take place.

RULES OF DFD Processes should be named and

numbered. Name should represent the process.

The direction of flow is from top to bottom and from left to right.

CONT.

The name of data stores ,sources and destination are written in a first letter capital.

A process must have minimum one data flow into it and one leaving it.

LEVELS OF DATA FLOW DIAGRAM

Level 1(High Level Diagram)

Level 2(Low Level Diagram)

LEVEL 1 (HIGH LEVEL DIAGRAMS)

This level (level 1) shows all processes at the first level of numbering, data stores, external entities and the data flows between them. The purpose of this level is to show the major and high-level processes of the system and their interrelation

EXAMPLE:-

LEVEL 2 (LOW LEVEL DIAGRAMS)

This level is decomposition of a process shown in a level-1 diagram, as such there should be a level-2 diagram for each and every process shown in a level-1 diagram .

EXAMPLE:-

IMPORTANCE OF DATA

FLOW DIAGRAMSOrganization:- Programmers use

data flow diagrams to plan exactly how their new program is going

Decision Making:- If there are usually known as "if-then" statements, and they tell the program what to do when given specific data to work with.

CONT..

Presentation:- when discussing a program with people is to use the code to explain what the program does and how it will do it.

Adaptability:- programmer uses a data flow diagram, the diagram will help the programmer be able to see what will happen

CONT..

Error detection:- sometimes it's difficult to pinpoint where exactly a problem is in the code, but with the help of a data flow diagram, a programmer can find the error in question and begin to figure out how to correct it.

REFERENCE

www.google.co.in

en.wikipedia.org

visualcase.com