Would you fuel a brand new car with dirty gasoline? That precisely, would be a bad migration! Migration does not belong to the obvious project activities of a professional unit. That is why  the following important and crucial aspects are often overlooked:

• What is with IT security? Which hurdles are to be overcome?
• To what extent does the legacy system differ from the target?
• How many modification / extensions are implemented in the legacy system?
• Where do the resources for migration/ development come from?
• Are the business resources available or do they still have to manage daily operative business activities?
• Is there experience with such a migration in your company?
• Is the HW procurement, development and preparation a part of the project? And have you allocated enough time for the procurement?
• Who is responsible for the migration of the interfaces?
• Have you planned several cycles  for your migration?