MDM Questions

Background:

15 Companies on 15 different Legacy Systems.

Phased SAP R3 rollout - one company at a time over x years.

Companies would 'live/maintain/create data' on their legacy systems until such time as they are converted over.

Thinking of using SAP MDM initially as a means of rationalizing like vendors, materials, and customers.

Thinking of using SAP MDM for help with conversion.

Ultimately, would like to use MDM as means of Central Data Management. Once all systems are live, idea would that there is only ONE representation of any given material.

Question 1: How 'good' is MDM at rationalizing/consolidating files? I've heard mixed comments. Why do some companies utilize services like Backoffice?

Question 2: Conversion related question. Legacy system 'A' has 50 vendor attributes. R3 'needs' 300 vendor attributes to run. MDM has 100 attributes. How are the other 200 attributes R3 requires accounted for/loaded?

Question 3: Suppose one of the 15 Legacy systems above is half on SAP and half on their Legacy system. What do companies do with respect to maintenance? Do it in both places? Do it in MDM and use MDM to update the legacy system (how are all the additional fields in the legacy system not in SAP MDM accounted for)?

Question 4: It appears as though MDM only maintains Basic or General data points, and NOT data related to a specific Company Code or Sales/Purchasing Organization. What do companies that want to maintain all their data centrally do? - do they try to model organizational structures in MDM or do they create part of the data creation in MDM and finish it off in R3?