Customer master Mapping

Question

Hi All,
I got a requirement to create a new mapping for Customer master data, few mappings are already existing in the system but as per my senior they are not sufficient to upload the full data into Data manager ...so I need to create a new Map.
Could you please guide me on the following
1.  What should be the approach in creating the Map for customer master
2. How to handle Check table and Value Table
3. Is there any way to use the old Mappings ( I mean can we copy / over write the mappings )
4. Roughly how many days it will take for completing this activity  ... I dont know any thing about the mapping, so need to go through the documentation, so request you to provide any links / docs
5. If any one has already handled customer master for MDM then cud u please send the mapping strategy / steps to me please.
Thanks in advnace
Waiting for your valuable inputs

Answer 1

The extent of the mapping depends heavily on your data model.  It sounds as though you would like to build an Import Map to populate data in the repository as opposed to building a syndication map.  Building the Import Maps is typically a pretty quick and easy process, and shouldn't take more than a day, even with a complex data model.  First I would find out how many fields are in your data model, and what the source is.  For example, if the source of the data is ECC, then it's pretty easy to get good documentation on the function of each field.  You can go to transaction WE60 (Idoc documentation) and search on an IDoc type (ie: DEBMAS or DEBMDM) to find the field descriptions.  If the client (or corresponding functional analyst) has already given you a functional mapping spreadsheet, then that will save you a lot of time, all you have to do is go build the map. 
When handling values in a lookup table, first you want to populate the lookup tables.  So if the extract is coming from ECC, you can use the generic extractor (transaction code: MDMGX) to extract check table data.  Then load this data into MDM using the Import Manager.  Once the lookup table data is loaded, then you can go load the main data.  When building the map, you can use automapping for the lookup values.  In the configuration options of the map, make sure to select automapping to True for the import server.  If there are values in your data that are not in the lookup table, you can choose to set the value to NULL, map it to another value, or pass the new value into the lookup table.  Typically lookup tables are used for maintaining data integrity, so it's not a good practice to map new values into it.  If you have new values, you should study them and find out why they weren't populated in your lookup tables from the extract of the source.
If you are experienced with building import maps it will only take 2-3 hours to build an import map (at the MOST).  If you don't have much experience, it may take a whole day because you will be learning as you go.