Before matters become a conflict, I will recommend a PM-to-PM discussion. Of course, I assume that everyone works for the same organization and the organization loses valuable man-hours to avoidable conflicts.
Where a conflict already exist, there is always an arbiter. The structure of an organization might also influence the means of resolution. While I do not expect such conflicts to occur in a project organization, it is fairly common place in a functional or matrix organization. In all cases, the project sponsor(s) should be able to reach the required compromise or resolution. Saving Changes...
Try and resolve it between yourselves before bringing a third party in. Is there a solution you can both be happy with? Failing that, is there a solution you can be happy in part (compromise)? What happens if you back down and go with the other person's view? Will it be worse, better, will it be the end of the world.? Failing all of these, bring in a third party to facilitate. Saving Changes...
Spaccarle la testa, Fabio! Its hard to answer. It depends on several factors including your knowledge about your peer and the organizational culture. I worked inside USA companies and French companies and the way to solve this differ. As you know people which have Latin blood behave quit different than other type of people. What I tried to apply (it is not easy for me due to my grandparents came from Italy) is negotiation techniques with a mix of SPIN Selling selling method techniques. Just in case we do not get an agreement I tried to find something above us. Saving Changes...
As always, it depends on the specific context of the situation.
Confronting the problem (not the person) directly and working with the other party to find a win-win is preferable to involving a third party, but if time is short and there's enough bad blood between you & your peer to prevent a productive discussion then a third party might be needed.
Confronting the problem not the person.
Discuss the problem in a calm manner and use inclusive words, such as "we." You will resolve more peer conflicts if you say something like "We should work this out," instead of, "You guys and I better settle this."
Avoid emphasizing your peers' character traits that annoy you. Focus on what they are saying instead of how they smell, sound or look. They often can't help their annoying characteristics, but they do have control over their words.
Explain how each person could benefit if there was no conflict. If there is something you need from the peers, suggest that you will be able to help them in the future.
The third party should be your last resource Saving Changes...
Kiron and Kevin suggestion are what I would do. Each conflict is different, but solving the problem is the goal. Is there is a conflict between individuals underneath, that is a different issue. Saving Changes...
Fabio: Thanks a million for posting such a thought-provoking question. It's great to see that there are already some excellent answers.
More details of the relationship between the individuals, their personalities, organizational culture and exct nature of the confict are obviously important.
However, as pointed out in several answers here, every effort should be made to resolve the conflict through an honest, person-to-person talk. It is only after this option has been exhausted should a third party be involved.
Some key principles would be:
1. Acknowledge the conflict: Being in denial will only prolong the conflict and make it worse.
2. Employ Empathy: Try and look at the conflict from the other party's point of view.
3. Focus on the issue rather than the personality or past history.
4. Actively look for creative, win-win solutions. Saving Changes...
you already got some great advice here. And like others also mentioned I find it oo a bit difficult to answer that question without any further information. Those situations are always very specific and subjective.
However, before involving a third party - which may through a dark light on your capabilities too - you should try to manage the conflict on your own and find a solution.
And of course it is preferred to create a win-win situation here with your colleague, but that is not always possible.
If so, involving a third party either for mediation or maybe even for escalation can be a way. That may end up in a win-lose situation for one of the parties but sometimes that is just what needs to happen.
Can you tell us, how the situation went meanwhile?