BS,
what is (could be) the "Functional" Difference between choice of Customer Forecast Management and Collaborative Demand Planning ?
The functional differences at a high level are spelled out in the help docs previously cited. Please don't expect me to do your homework for you. Alternatively, you could log onto SAP Service Marketplace and look through the many documents posted there on the subject.
In any case, I think you are asking the wrong question. A better question would be "what best meets the business requirements of my business." This is the question you pay your experienced consultants to answer. If you take it upon yourself to pre-decide the solution, you are missing out on the benefits of the expertise of the consulting resource.
if I give an access to a data view to my customers on the internet, they can load a selection id and key in a forecast .....
This is possible
Second scenario: I don't give my customer any access to data views because they are too big and busy to be doing this all the time. They send a file by an email....
This is possible
A third scenario is customer doesn't send anything. Instead I develop an interface to read customer time series ....
This is possible.
Then there is collaborative sales forecasting in SNC that I am yet to read re its use cases for the end objectives.
The right consulting company will have a library of previous engagements they will share with you on this subject. If you want to get started sooner, you can also log onto SAP Service Marketplace, and download some of their 'executive level' presentation documents, or customer experience documents.
Best Regards,
DB49