TMM Best Practice - response (1) by ccurry

You can only map one object to another if they are both in the same project, so you would typically create separate data representations (DRs) for File, Stage and Base, then map File to Stage and map Stage to Base. You can import the DRs using the blank templates provided by TMM installer or you can use pre-defined ERwin reports to generate the import files if you are using ERwin.
If you have 3 models for each source, then you would have an additional 3 DRs for each source.
I recommend the TMM tutorial to teach you the basics - it is found in pdf format under My Documents\Teradata Mapping Manager\Documents.