Data Flow Diagram tips
======================


  1. No double arrows allowed.

     <-------->     <----- No


  2. Must use all four symbols in your diagram.


  3. A box with rounded corners is the same as a circle.


  4. Arrows should be labeled with the data that is flowing,
     Not the process that is happening.
     

  5. A data store probably doesn't process the data.
     It stores the data, and maybe sends the data to a process.


  6. External entities and processes should be labeled as what they are,
     not with a description of what they do. The data flowing to and from
     tells us what they are doing.
     A few words is adequate for a system, function, external entity, or
     a data store. Don't go on and on.


  7. Do not delete your lab-4 diagram.

     Some students do not have their first diagram from the lab yet.
     Do not skip this assignment.


This tips list was developed from all the mistakes I'm seeing.