Know how the executives want the ROSI positioned--cash savings,productivity gains, increase in security--and move forward that way.Many sources also report that making the ROSI case interactive forexecutives--allowing them to tweak variables and watch what happens tothe ROSI--is by far the single most effective selling tool you canuse. "The key is not to be defensive about the data, as I think ITsometimes can be," IST's Jacobson says. "Don't defend the model;explain it."

Nigriny thinks there are other, underrated sales skills CSOs need tofoster in themselves. A general familiarity with accounting ispriceless, he says. Also, "You have to be good at public speaking andat PowerPoint engineering. If you're speaking to the CFO, expect himto do some number crunching; have your numbers ready for him. The CEO?The executive summary is far more important. Talk to the CFO ahead oftime; you'll have his support, and the CEO won't have to sit throughthe numbers discussion," says Nigriny.

We weren't kidding when we said this is laborious, intensive work. ToNigriny, ROSI is fractallike, in that the closer he examines hissituation, the more intricate it becomes. "Every time I thought I hadit covered, a raft of new variables came up. I've just got this swagof numbers here I have to deal with," a nonplussed Nigriny says.

It's up to the CSO to set the thresholds of what's really needed for aparticular scenario. You can make ROSI as simple or as complicated asyou think is necessary, and an obvious tenet that emerges is that asimpler ROSI will be somewhat less accurate than a detailed ROSI, butthe detailed version will require ever more legwork.