According to The Standish Group report, one of the primary causes of data migration project
overruns and failures is a lack of understanding of the source data prior to data movement.
This study involved a series of focus groups with IT executives in four US cities. According to
these executives, 60-80 percent of the effort in data migration projects is expended on trying to
understand and map the source data. They also indicate that this was an iterative process without
a predictable endpoint. The study concludes that if source data could be understood
more efficiently and accurately, then the project’s business value could be delivered on time, or
even accelerated.