A Beginner's Guide to Data Flow Diagrams

As an ecommerce business owner, there are a multitude of processes and systems to manage on a daily basis. To help streamline operations and increase efficiency, data flow diagrams (DFDs) can be an invaluable tool. Whether you're just starting out or looking to refine your existing ecommerce operations, understanding how to use DFDs can be a game changer.

What is a data flow diagram (DFD)?

A data flow diagram is a visual representation of a system or process that shows how data moves between different entities and processes within the system. It can be used to identify inefficiencies, redundancies, and other areas for improvement in a system or process.

Data Flow Diagram Symbols

There are four main symbols used in DFDs:

External Entity

An external entity is anything outside of the system being diagrammed that interacts with the system in some way. This could be a person, another system, or any other entity that sends or receives data from the system.

Process

A process represents how data is changed or transformed within the system. This could be anything from entering data into a database to calculating shipping charges for an order.

Data Store

A data store is any place where data is stored within the system. This could be a database, file, or any other location where data is stored long term.

Data Flow

A data flow represents how data moves between different entities or processes within the system. This could be a physical transfer of data, like a file being sent from one system to another, or a logical transfer of data, like a calculation being passed from one process to another within the system.

Levels of Data Flow Diagrams

There are four main levels of DFDs:

Level 0: Context Diagram

The context diagram is the highest level of the DFD and shows the overall system being diagrammed, including all external entities and data flows.

Level 1: Process Decomposition

The level 1 diagram breaks down the processes within the context diagram into more detail, showing how data moves between different processes within the system.

Level 2: Deeper Dives

Level 2 diagrams go into even more detail, breaking down each process from the level 1 diagram into smaller sub-processes and data flows.

Level3: Increasing Complexity

Level 3 diagrams are even more detailed, breaking down each sub-process from the level 2 diagram into smaller sub-processes and data flows. This level of detail is typically only used for complex systems.

Data Flow Diagram Examples

Here are a few examples of what DFDs can look like:

1. Level 0 DFD

2. Level 1 DFD

3. Level 2 DFD

How to Make a Data Flow Diagram

Here are the steps you can follow to create a DFD:

1. Select a system or process.

Determine the system or process you want to diagram. This could be anything from your entire ecommerce platform to just one aspect of your business operations.

2. Categorize related business activities.

Group related activities together and determine what data moves between these activities.

3. Draw a Context DFD.

Use the external entities and data flows identified in step 2 to create a context diagram of the system or process.

4. Check your work.

Review your context diagram to ensure it accurately represents the system or process being diagrammed and that all external entities and data flows are included.

5. Create child diagrams.

If there are too many processes or data flows to add to the context diagram, break them down into child diagrams.

6. Expand processes into Level 1 DFDs.

Create more detailed diagrams for each process identified in the context diagram, showing how data flows between each process.

7. Repeat as needed.

Add more levels of detail as needed to create a comprehensive diagram of the system or process being analyzed.

Perfecting Your Process

By understanding how to use DFDs, ecommerce businesses can streamline operations, improve efficiency, and ultimately increase revenue. Whether you're just starting out or looking to refine your existing operations, taking the time to create a comprehensive DFD can be well worth the effort.