Degree of simplicity is an important criteria for McDonald's when IT evaluates a new product. How easy the product is to implement and how fast IT can deploy it matter as much as functionality, he says.

Like a new car, a new IT system starts to decay the moment you turn it on. Servers, laptops and smartphones are machines, after all, and software gets gummed up as it takes in data and interacts with other software. Aging technology requires extra nurturing.

Because every piece of IT has a rate of decay, Wander says, CIOs should create a life plan for each one. This helps keep down how many layers of technology have to be integrated. It also helps companies avoid getting stuck with technology dregs, he says. PowerBuilder was once a hot development tool. Then Sybase, itself a declining database vendor, bought PowerBuilder and the tool lost momentum, he says. "If you don't deal with that complexity, you end up with systems difficult to maintain because you can't get people. Then it's an operational risk."

At McDonald's, Weick's team categorizes technologies as explore and innovate, commercialize and deploy, or enhance and maintain. IT works with business leaders to set investment levels and plans for how each system will move through the cycle. Continuous pruning is a challenge for CIOs, he says. "It's easier to add something new than retire something old. It builds up like plaque in a coronary artery."