Getting good information isn't easy. Take, for example, the transparency of your cost structure. "You need good information around all technology costs and investments," says Merrill Lynch's Balliet. In 1999 and 2000, he and his team looked hard at all the IT dollars and categorized them into service "buckets," then put them in chargeback buckets related to those activities. For example, Balliet says that they created a phone monitoring tool and told some units, "You pay for the calls you make."

In addition, you must update the database regularly. "You need to have the constant status of each project so you can react quickly to market changes," says Balliet.

It's still hard to make tough decisions on whether to undertake - or cancel - projects. Kifer, no slouch at portfolio management, says DHL Americas currently has 20 percent more projects in its portfolio than it can support. "We won't probably start half of those," he says. "[But] an organization has a tendency to say, You'll figure out a way to make those work."

It's an additional time constraint on busy executives. Good portfolio management means good IT governance means regular IT governance committee meetings. "Just about every company today has its people stretched," says Chasney. As noted earlier in the story, that concern is addressed at DHL Americas, where the lieutenants of time-constrained senior vice presidents serve on the project portfolio review board.

In the grand scheme, however, the challenges of implementing portfolio management pale in comparison to the value it brings to your IT investments. "It forces IT and businesspeople to talk about investments from a business perspective," says Weill. "That's its most powerful feature."