Some Background ...
At any time of the day or night, you can be sure that Data Migration is going on somewhere in the world.
Over the years, it has become a familiar area and cannot be considered 'Rocket Science'.
It consists of a series of standard Tasks, for which methods have been established.
There is a choice of Vendors offering a range of products to solve these problems. These typically are in the $250,000 price range which encouraged Microsoft to enter the areena. and offer Data Transformation Services,'DTS', which lowered the bar tremendously.
This, in turn, forced the big-ticket' vendors to emphasise the 'Enterprise' level of their offerings, and so Microsoft DTS became 'Departmental' and then we have the situation where small groups become familiar in DTS.
Sooner or later these two areas of activity have to be reconciled, which (Guess What !) creates work for us as Data Analysts - isn't life wonderful (sometimes) !!!

Microsoft with their Unified Dimensional Model,realises the importance of a Generalised Data Model to integrate data from various sources and help End-Users to get a 'Single View of the Truth' for BI and KPIs.