We help IT Professionals succeed at work.

Data Flow Diagram Level1

Delidumrul asked
Last Modified: 2013-11-29
Hi All,

I am working on the database assignment. I completed the context diagram. At the moment, I am trying to draw data flow diagram level1. I must define external entities, process and data store. I finished external entities. However, I do not know how to identify process and data store. Does anyone has idea about it?
Watch Question


I uploaded the picture of context diagram. This could help you understand the question easier.

The use of DFD's are to simplify the process of designing a database system.  So the thing to do is try to not think too deeply about it.  Your context diagram is too complex and almost a level 1 DFD.

Your datastore would be the 'Rental System Database'  This will be linked to the process 'DVD Rental system'.  If the system is for a local store, you'll only have the one datastore.  Although you can represent the same datastore numerous times on a diagram to keep it clean and tidy.

Your processes for a level 1 DFD would be:  

'Search Customer details''
'Save customer details to datastore (Rental System Database)
'Update customer details'
'Update DVD's issued'
Update DVD's returned'
'Review stock levels'

Hope this helps.  Remember a DFD is a tool to help you design, not to confuse you :-)


Thanks for reply,

I updated the DFD1. How it looks?


Looks like you're almost there.  You've numbered everything well and used the correct templates.  When a member uses a terminal to search it queries the data store so you'll need to add the data store next to that process also.


What kind of data stores is required for this project?


When we look at the context diagram, there are 5 data flows from Shop assistant to the system such as renewal of DVD, return of DVD, Member details and so on. Do you think I should create data store for each data flow?


It is the updated version. I need some feedbacks.

This one is on us!
(Get your first solution completely free - no credit card required)


Hello Vee_Mod,

I have been still working on this project. Therefore, I will have some other questions about it.


Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Join our community and discover your potential

Experts Exchange is the only place where you can interact directly with leading experts in the technology field. Become a member today and access the collective knowledge of thousands of technology experts.

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.