It happens in every workplace: Two employees have a classic personality conflict and bicker constantly. Due to the nature of their jobs, they must interact with each other. What’s the best way to stop their petty squabbling?
You’re the boss: Put your foot down. Tell both employees in no uncertain terms that they need to put their petty differences behind them. While they do not have to like each other, they do need to act professionally and respectfully.
Manage their performance only; do not try to solve their interpersonal differences if they are not job-related. Finally, warn them of potential disciplinary consequences if their behavior does not change.
Don’t allow the employees to give you excuses or point the finger at the other person. They must take responsibility for their own behavior, and the expectations you have defined for them are not up for negotiation.