At the other end of the spectrum is a wholesale tool/platform/database/environment change. differently for performance. Different data may be stored in different repositories. Product workflows may change. User tools will have to be relearned. Knowing one tool/platform/database/environment is certainly very helpful, but while the functionality may be analogous the implementation details will differ.
If you are making a significant change to the environment, be sure to consider the time required to re-develop all of the existing analytical artifacts. This can become an extremely expensive activity. Let’s say that japan rcs data ten thousand reports have to be migrated, and that the migration of a single report will take an average of one day to complete. (This is a grossly overly optimistic estimate, since some of the more complex reports and applications can take weeks to migrate and validate, but let’s go with it as a super-conservative average.) That’s ten-thousand person-days, or 40 person years, and at $100k per year, that’s at minimum of $4m just for report migration.
If you want to finish in a year, you’re going to have to find forty people to migrate those reports non-stop, you’re going to spend four million dollars, and that investment is not generating any new business value.