As a manager, you will always be asked to do more things.  On top of what you have already signed up to do, people will drop by  your cube, catch your arm in the hall, and corner you in meetings and  will come up with additional things to add to the already full plate of  tasks that you have in front of you. 

It can be all too easy for us to  deal with these situations by simply saying “I’ll do that”. Do this  enough, and all too quickly you’ll discover that you are now juggling  too much for any one person to get done. 

When this happens, you need to  start to use the greatest skill that a manager has: focus.