"Hey, you got a minute?" That's a question - not a demand. Don't get angry with the interrupter if you answered, "Sure!" to their question. General rule: If you cannot eliminate the interruption, make the interruption as short as possible. 1. Meet them at the door. When people arrive to interrupt, meet them at the door and talk outside of your office. Letting them in may add minutes to the interruption.
2. Stand Up! When someone shows up unannounced, keep standing until you decide if you want the conversation to continue. Standing is not comfortable for most people and the length of most interruptions is in direct proportion to the comfort level of the interrupter.
3. You're the Timekeeper. Signal the end of the time allotted by politely saying, "One more thing before you go." Be respectful but take control. Remember that this is your office and you're responsible for the time here.
4. Get rid of extra chairs in your office. You can always pull one from somewhere else if you need it.
5. Positioning. Arrange your office so that your desk doesn't face the door. People are less likely to interrupt if they can't see your face.
Henry Ford was always dropping into the offices of his company's executives. When asked why he didn't have them come to him, he replied, "Well, I'll tell you. I've found that I can leave the other fellow's office a lot quicker than I can get him to leave mine."