Grantham also strongly suggested creating a data center cable strategy to ensure resiliency, so that no single floor-tile accident, for example, can take out an entire network. He also recommended documenting the entire storage infrastructure, even if you have a good storage resource management tool.

"I have a very good SRM tool. However, I still have my guys walk through racks of servers counting Fibre cables and saying this server is not on our list," he said. "We found 11 servers not documented anywhere on our SAN, and some of them were 64-processor servers running critical business [processes]."

The No. 1 killer of all projects is lack of funding, Grantham said. If, as an IT manager, you think it's going to cost a certain amount, fight for that amount, he said.

Grantham also echoed a common mantra of IT project managers: "Communications, communications, communications."

Make sure you have a clear division of responsibilities, and form a small dedicated team, he said. At Nationwide, a team made up of Grantham, two engineers and one vendor contractor performed the migration.