It's one of the reasons I counsel my clients on interviewing to focus solely on attitude and aptitude. Those are the two things you cannot manage or train.
But eventually we all come into contact with a moody employee - someone who's attitude swings up-and-down all too frequently.
How do you manage a moody employee?
The first step is to focus on why they're moody. Is it a personal issue, or an issue with you, or your company?
Annette Fazio of Seacoast Online has some good tips. All deal with communicating with that employee and asking him or her:
What do you like best about working here?
What do you like least?
What specifically do you like about the way the office/business is handled?
How do you think the phone should be answered? How many rings? Why?
Ask for the employee's solutions to the problem. If he or she doesn't see a problem, that's another red flag. Unless you are skilled at open-ended questions, write them out first. We tend to ask closed-ended questions that require a yes or no answer, and they don't lead you to any solutions. Your aim is to get your employee to talk.
Asking open-ended questions puts the burden on the other person to be responsible for their own attitude and behavior.
Ask permission to take notes. It makes a statement about the serious commitment you have to the employee and your team, and the notes will be handy if you need to have future conversations regarding the situation.
Notice the questions are open-ended; they require more than just a 'yes' or 'no' answer.
This takes care of the business issues that can cause moodiness. If it's personal, don't get into the issues - but remind that employee you expect that everyone's personal life should be left at the door when work starts.
If an employee can't do that, then it's time to start counseling that person out. Negativity is a killer in any workplace.