Context Diagrams for MM (1 Viewer)

[honeybuzz]

Ok so I'm about to rip my hair out!!! i have an assignmnt that was due 22nd of June and I still haven't handed it in i had an extension so all is fine BUT I can't do these stupid context diagrams!!!! I have no idea what to put in them and it's driving me crazy can someone help me?

The whole assignment is creating an interactive website informing future IPT students of the benefits of IPT (newsflash there is NONE!!). So I need to draw a context diagram for it and a Data Flow Diagram that demonstrates a student accessing the MM product.

I have the context diagram done but I'm positive it's wrong but I'm willing to leave that But I have NO idea what to put in the DFD help PLEASE before I TIA

 

[priesty]

LOL...... deep breath... ok

Context Diagram is simply a Circle (process) with "interactive website" labelled within it. Context Diagram is a VERY VERY VERY SIMPLISTIC and abstract view of the entire system. not much detail needed at all... you might also like to include a rectangle (external entity) with "student" labelled in it. and join the two together with an arrow and voila! But hmm I see in this case the DFD is to show the student accessing it right? Then you would add this external entity into the DFD --->

DFD is a bit more detail. The key element of the Data Flow Diagram is the actual specific data items that you write along the flow lines to highlight the movement of data throughout the system. So maybe it'll be an addition to the above diagram by taking a closer look at what actually is inside the "website" Process. So what have you got in there? Perhaps the website requires a log in system? Wouldn't all the info be stored somewhere? So in that case you would link up the "website" process to the "Users Database" external storage symbol. then along the lines you would write something along the lines of "username/password" (on the arrow from the website to the database) and then the database would return a flag of somesort telling you if the username and password are correct and match "acceptace message/incorrect login" or something along those lines (on the arrow back from the database to the process of the website). That's just an example, if such a thing doesnt exist then it wouldnt be needed, and the only diff between the Context and DFD is the student rectangle and MAKE SURE IN DFD THAT YOU SPECIFICALLY MENTION WHAT IS BEING TRASNFERED ALONG THE FLOW LINES... haha sorry for the caps but its VITAL! lol...

nething else?

Hope this helps....

 

[honeybuzz]

I think i understand a little more now....so thanks!!! but there's no password which I think is what is giving me the biggest problem..... and also labelling the arrows I have no idea what to label them.

So if I do a .......... Square?? labelled student and then draw an arrow to a circle and label the circle (insert correct answer here) and then to the side of that put another circle labelled server? with an arrow going to and from it and label the arrows (insert another correct answer here) and then from the 2nd circle do another arrow and draw another circle which is the site?? does that work or does none of it make sense?

SORRY and thanks again!

 

[priesty]

hmmm i see where ur coming from, and i believe ur talking in regards to the DFD yes?

the context diagram would be muchmore simpler than all that, and a circle labelled "Website" would be sufficient when joined to a Rectangle labelled Student. In context diagram you dont need to label the arrows with any descriptions of data flow.

in the data flow, does the question require you to have the server? the server is more a place where the files of the website is stored, so instead of that being a circle (a process) you would make the "website" circle joined to one of those data store symbols of the DFD which is the rectangle with the right vertical side missing.

The characteristics of a Data Flow diagram require the arrows to describe the data actually moving between the different processes, entities and storage spaces. This can include things like "request for page" "report (on what results have occured within the process for example)" "website page requested" "username" "password" "userID" and any other piece of information that might be inputted or outputted by processes and these symbols to other parts of the diagram.

understanding a bit more?