Hello Everyone
Here is the DFD PPT. I found it onine while searching for DFD and Context Level diagram. Hope this is useful
Thanks
Sonavi
I think Adrian has got all of us busy. Sonavi is right, I wish there were some senor BA's which would give their comments and suggestions for newcomers like us. I have gone ahead and made Context Diagram02.
Adrain, it is hard to find noun phrases to name a data flow. i think it is different from my first one in which i missed up quite a few flows and is close to what Sonavi has made with a few variations. I have added webservices as an indirect flow which I was not too sure whether it should be there or not.
In the requirements document , it is mentioned that the OBS makes use of webservices but has not been elaborated. It talks about it in the context of technical help if the web services gets disrupted. I am not sure if I have understood it properly.
Thanks:- Jay
Hi Jay
I checked your diagram and it looks great. I have few questions regarding the context level diagram. What i have read and understood was that at the context level diagram we show only the external entities interacting with the main process which is why it is Level 0 Diagram and at the later stage like at the level 1 diagram we show all the sub-process like (deposit cash, cheque, withdraw cash, etc). I am not sure which way is correct so lets wait for Sr.Business analysts opinion as to how we should proceed.
-Sonavi
Hello Sonavi/Adrian
There are a lot of doubts coming to my mind too as to the context diagram. From what I have read, it is used to define the scope of the project at a high level without going into the details as of how u would be doing it.
The goal of the customers for using the ATM is to be able to do certain transactions ie withdraw cash etcc. This should be done in a secure way would be the need of the system. I was wondering as to if the login should be shown in the Context diagram or in the level 1 diagram.
I think your thought process is correct. After the context diagram, we would be decomposing it to Level 1 diagram in which we would show the major functionalites for this prosses without going into the details. Then I think we can decompose each functionality to the level of detail required. That is my thought process and understanding. We will wait for the feedback from Adrain and any other comments and suggestions.
Adrain, i was wondering if it is a right time to ask a few doubts I had in mind. I hope you are not shocked at my question???
Can we mix and match our diagrams ie data flow and use case model ???
show high level design with context diagram only OR context diagram and level 1 diagram .
Then switch over to use case model and elaborate the functionality of each use case with narratives bu showing all the basic flow, preconditions etc in the use case narrative and support it with flow charts if requried.
Hello Adrain and team members
Below is a link that gives good info in data flow diagrams and context diagrams. After reading this, i have made some changes to my context diagram which I am uploading right now.
http://www.cems.uwe.ac.uk/~tdrewry/dfds.htm
Thanks :- Jay
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