"We wanted to make sure the people familiar with our environment stayed," Richards said.

Smith suggests building in a contract clause that specifies retention periods for staffers working with your application, with reduced contract payments if staffers leave sooner. "Service levels do change when people leave," he said. "Even if you end up with a better person, they still have to come up to speed."

Manage the Move

Some acquisitions entail a move to a new data center, which everyone agrees is disruptive. For instance, when two major automated teller machine service providers -- Concord EFS Inc. and Star Systems Inc. -- merged and consolidated data centers in 2001, "it threw a wrench into our development plans," said John Dick, chief information officer at Regions Financial Corp. in Birmingham, Ala.

The bank wasn't involved with the heavy lifting, but it did have to do extensive end-user testing, which meant pushing other strategic projects to the back burner. The conversion also required negotiating over who paid for what and whether the bank would be compensated for its extra efforts.