Data flow diagrams (1 Viewer)

[Marina89]

I'm looking over a data flow diagram for the school timetable system in the Samuel Davis book and it has 'Admin staff' as an external entity. I thought that participants are part of the system and therefore they aren't considered to be an external entity..

Someone please explain?

 

[Lwaxana]

External entity = any person or organisation that sends data to or receives data from the system

 

[Kat92]

Yes, data flows can go both forward and backwards.

 

[alcalder]

Not that I have the diagram in front of me, but also you need to remember that the making of such diagrams also includes a lot of internal politics. School timetabling is usually done by the AP or VP and teaching staff below him. Admin staff are just adjuncts to the school and are seen as such by most on the teaching side of things.

Others (like you and me) know and understand that the Admin staff are actually the heart and soul of a school and SHOULD be included in the whole of such a data flow diagram because they are the ones who input, output, implement, formulate, distribute etc the most.

 

[Marina89]

Ok that makes sense. Thanks guys =)