Sonna and Justin are two long-time supervisors in the production department of a manufacturing firm who do not get along. Their dislike of each other has started to become a problem in the workplace, and now some of Omar's team members are starting to squabble with Justin's team members. After overhearing Omar and Justin's shouting match on the factory floor this morning, their boss Karen is going to take action. She knows that the supervisors need to have a good working relationship, and their teams need to communicate well to keep things running smoothly. Working things out is very important because Karen would have a very hard time replacing Omar or Justin with someone who is equally skilled and experienced. 

Describe this situation using conflict and negotiation strategies and discuss how Karen can address the situation.