...manage business critical tools in several, disparate locations means that you create multiple points of failure, multipleenvironments to manage and a potentially complex network infrastructure to maintain and support. Imagine your business...
http://www.computerweekly.com/DowntimePDF/pdf/star_white_paper_MPLS.pdf
...encapsulates either of the previous situations. Who Can Perform the Migration? Due to the complexities of multipleenvironments, multiple operating systems, testing, rollouts, operational planning, high availability strategies, etc...
http://hosteddocs.ittoolbox.com/SiebelDBMigration.pdf