6. Wouldn't it be a better investment to focus on retention rather than recruiting?

It certainly costs plenty to recruit and train a new employee. You may ultimately end up paying as much as 100 percent of a departing employee's salary or more, just to get a replacement up and running, according to Berry. Then again, 100 percent retention is a bad idea too. Too little turnover "will limit the amount you can learn from the outside", says Tim Bosse, executive vice president for professional staffing company Hudson IT & Telecommunications. It can also lead to a clogging at the top and a lack of entry-level positions at the bottom.

IT leaders should instead strike a balance between recruiting and retention efforts. Add "roles" and "rotation" to the list and you have the four R's of staffing, says Forrester's Bright. And they're all interrelated. Yet Bright says he can count on one hand the number of IT leaders who keep continuous focus on all of them. "It's amazing the lengths people will go to avoid having to create a fully fleshed-out talent management strategy," says Bright. "They focus on one area only after it's starting to cause problems."

There will be seasonal or cyclical reasons to focus on one piece of the staffing puzzle more than another. But generally speaking, the key to success is to be proactive about managing the entire staffing spectrum. "You can't tackle any of these issues in a vacuum," says Bright.