Software Development Lifecycle (SDLC): End-to-End Overview

What is a Data Flow Diagram?

A Data Flow Diagram (DFD) shows how data moves through a system.

It helps visualize Data sources, Data processing, Data storage and Data output

Components of DFD

1. Process: Represents data processing. ex: Process Payment

2. Data Store: Represents where data is stored. ex: Database

3. External Entity: Represents outside systems or users. ex: Customer

4. Data Flow: Represents movement of data. ex: Payment Details

DFD Levels

Level 0 (Context Diagram)

It Represents High-level overview of the entire system.

Level 1

It Breaks down main processes.

Level 2

It Represents more detailed breakdown.