Hello Adrian
Thanks a lot for your feedback. I apologize for the mistakes and my limited knowledge. This is my first attempt of a context diagram or anything I will be creating in the near future. Be prepared for the worst but the efforts are sincere. I hope to give it my best and am glad there are other team members participating too.
Thanks a lot : Jay
Hi Adrian
Thank you for your valuable advise. I have few questions, you mentioned that the relationships among processes and entities in a Context Diagram show Data Flow and not actions. Therefore the relationships should not be named as "Verb Noun" but just "Noun".
1. At the Level 0 diagram do we just show the external entities interacting with the system and not show different process how the systems is interacting with the external entities like ( cash withdraw, deposit, error message, transfer between a/c, print balance, etc)
2. If we show just the external entities interacting with the system then how do you name them for eg ( customer interacting with Cyber ATM bank)
3. What is the next step after the Level 0 diagram?
Thanks
sonavi
Hi Jay & Sonavi,
You are most welcome!
Here are some quick answers to Sonavi's questions:
I think that you guys should now take another try at creating the Level 0 and maybe Level 1 of the Data Flow Diagram. You should both do it independently since there isn't just one "right/exact" way of modeling this.
BUT FIRST: However, before you guys move on to that step, you should Google "Data Flow Diagram" and "Context Diagram" and each one of you should post a short tutorial on the subject. This will force you to learn the subject matter and make it stick. Focus on: What is a Data Flow Diagram, What is a Context Diagram, What are the main symbols of the DFD and what do they represent, a couple of best practices when creating DFDs. FYI: There are two popular notations for DFDs: "Gane-Sarson" and "Yourdon-DeMarco" named after the brilliant guys who came up with this stuff. For some reason, don't ask me why, I have predominantly used the "Gane-Sarson" notation - maybe it has to do with the available notation in my modeling software.
Here are some links to get you started:
Up to the challenge???
;-) Adrian
Wow, that was a great explanation. I am ready for the Challenge!!!. I will post a short tutorial on DFD / Context diagram and start working on the DFD diagram for cyber bank ATM example.
I have another request from all the Sr.Business Analyst. Adrian is being very helpful in explaining the concept and giving his valuable advise and suggestion and we are very thankful to him that he is explaining and guiding us. I would request even other Sr.Business Analyst to please help new people like us by giving their advise and suggestions and helping us to learn more.
-Sonavi
Hello Everyone,
I found this wonderful PPT on DFD online. Hope this can help others also i found it useful for me.
I have attached the Context Level Diagram for Bank ATM example. I had few questions while working on context level diagram. I was not able to attach two files at the same time so i am attaching the DFD PPT in my next message.
1. I read online in a document that we dont include data store in the context level diagram, but we use it in the next level diagrams. Is this correct?
2. I didnt know the exact procedure as to how the cheques and non-cash instruments will be collected from the ATM. Is there a seperate process for that or do the cyber bank employees go and collect them. I have drawn a two-way process in the context level diagram is that how we are supossed to handle.
3. I had hard time in naming the realtionships becasue as suggested by Adrian i didnt use the verbs. Please correct me if i need to change the names of the realationships.
I would appreciate if all the Sr. Business Analysts can point out my mistakes and give their valuable advise.
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