He says limiting the number of vendors a company buys from simplifies choices, contributes to uniform standards and encourages those select vendors to offer executive briefings, technology previews and other kinds of preferred services.

But Griesbaum warns of hubris when the IT shop buys for itself. He says IT may make the business units go through detailed justifications for products but then forget the rules for its own purchases. "When you get a bunch of technical folks together... they get enamored with the technology," he says.

He recalls buying a software development and testing tool that didn't work out completely as planned. "We didn't go through the rigor that we should have and maybe trusted some things the vendor said a little too much," Griesbaum explains. "Sometimes we are our own worst enemy."