An open-door policy sounds like a great management idea--until the reality of a busy day intrudes. "I want to be available and accessible, but I really hate you for interrupting me," is how Jim Lucas, president of Luman Consultants, in Shawnee Mission, Kans., describes the feeling. So 10 years ago Lucas instituted a "modified open-door policy," in which his office door acts as a signal. "An open door means come in; I truly am available. A partially open door means I'm pretty busy, but come in if it's really important. And a closed door means I'm about to explode; come in if it's a life-threatening emergency," Lucas explains. "Using the door as body language cuts out all the baloney."