"Be careful not to schedule transitions in a way that leaves your IT operations unsupported or unfulfilled as you change vendors," he says. "This process needs to be managed carefully to assure your services are continuous and that the two providers do not interfere with each other."
On the other hand, not all services should be redundant during the transition, he adds. "In our IT management services, we do not want to be monitoring and responding to an outage if another group is also doing the same. Too many hands on your operations could lead to more problems."
"In general, we advise not to fire a vendor until a suitable alternative is ready to go," notes Eric Leland, a partner at tech strategy and Web development firm FivePaths. "While this can be costly on the vendor services side, it can save a ton of cost in system downtime, work-arounds, switching systems, and change management."
In fact, your transition will go much smoother if your old and new vendors can speak directly to each other, says Leverage Corporation's Harber.
"Your new flame and your soon-to-be-ex should definitely meet," says Harber, "primarily so the new vendor can get a complete snapshot of the environment and services being replaced. The vendor being replaced will have a much more complete picture than the new vendor will be able to develop initially, and the company will benefit from that information being shared."
And then cut the cord.
"Trying to maintain a residual relationship (the business equivalent of 'just friends') can lead to complications down the road," Harber adds. "When it is time for the relationship to end, it will be easiest if the relationship ends completely."
IT divorce tip No. 3: Don't get lost in the cloudJust because a vendor is providing service in the cloud doesn't make it any easier to break it off and take up with someone new. In some ways, terminating a cloud provider is more complicated, notes FivePaths' Leland.
"With cloud-based applications, the strategy for firing vendors has changed," he says. "The risk of losing everything -- the service plus all data -- is increased, as many of these service providers manage both. Companies should investigate what critical services the vendor offers and how much of the data is critical for daily operations and customer satisfaction. Would the loss be visible or invisible to customers? What internal operations would be affected, and how critical would this be?"
Leverage Corporation's Harber says you need to treat virtual breakups even more carefully than real-world ones to avoid losing access to critical functionality or important data.