For a school project, I need to make a DFD for an educational game, where both students and teachers need to be able to view the game's leaderboard.
Currently in my diagram, "Student" and "Teacher" are seperate external entities, "View leaderboard" is a process, and the leaderboard data is stored in a data store called "Leaderboard".
To represent this, can I use the same process for both entities:
or must I create separate processes for each entity like this:
I asked this question on StackExchange and got an answer.
To summarise the answer, in the Yourdon & Demarco DFD notation, there are 2 ways I can represent the situation above:
I could use a single process, like depicted in my first picture. In order to indicate that only one entity receives data at a time, I can put a
+
symbol in a rounded circle between the two outgoing flows, which would mean “or”.I could create a new external entity that would be a combination of the Student and Teacher entities. That way, I would only have to use a single process.