I have two very talented people on my team (of 28) who have a great passion for the business and their areas of responsibility. I am satisfied with their individual performance. The problem is they do not work well together. There is a lack of trust and respect for one another and when they need to collaborate we are sometimes delayed because of the time needed to work through the relationship issues between the two of them. This of course has an impact on the team at large. The three of us have had 2 lengthy conversations about this and they have attempted to resolve on their own as well but these attempts have only resulted in temporary changes in behavior. I am not (yet) at a place where I am contemplating job action or reassignment with either of them. I am looking for another step that would help them work better together. What do you think? Any suggestions about next steps?
The business impact of ineffective co-worker relations cannot be understated. With the size of your team, I can only imagine that others have not only witnessed this lack in partnership, they have been personally affected in their own roles. I can also relate to your comment surrounding 'temporary' progress; this often happens following triangular meetings with the leader. The recency effect is also observable, and studies have shown prior unwanted behavior becomes visible within 4-6 months.
As I'm unclear of your direct reports' actual job functions, you do note that their positions come into contact with one another for collaboration purposes. This piece is key, in that the business or organization requires the partnership for the sole purpose of business. My guess is that during your first formal sit down, the three of you attempted to bring the issues out on the table. Did you sense both parties equally contributing to the conversation or was one dominating the discussion? Did you call out your expectations and/or opinions at appropriate times? My guess is you did interject, when necessary. My rule of thumb is to allow the first meeting to be more of an "airing of issues" and then suggest the leader pull back in attempt for the two individuals to handle future interactions professionally. It appears the desired behavior was absent, hence you calling the second meeting. Although you shared you were not yet contemplating job action, I might have suggested stressing during the second discussion, specifically how their lack of teamwork is affecting the business overall. Also, that it is their employer that requires the ongoing partnership. I would've refrained from utilizing disciplinary action wording here, however allowing the two to 'fill in the blanks' by your calculated word choice and tone of the discussion. It is also helpful to call out the elephant in the room of the realization that the two of them will probably never become friends outside of work or interact socially, although their employer needs full professionalism during work hours.
I do know of situations where the business would face undue hardship as a result of releasing either of the employees at hand (simply due to their exceptional individual performance). As an alternative, one creative step to try is the Co-Worker Business Agreement or Contract. This process is utilized by both HR professionals and mediators. This Agreement is essentially created by both parties, whereas each party drafts up to five requests that would need to be fulfilled by their co-worker. Some examples might include: 1. I need my co-worker to inform me, via e-mail or phone, of any current customer dilemma that might directly impact my position 2. I need my co-worker to cc: me on any correspondence sent to my location or business partners 3. I need my co-worker to respect my personal flex-time (and refrain from inappropriate comments/rumors with other co-workers) etc etc. As the leader, you would request that each subordinate independently draft their five. Then you would hold a follow up meeting with all three of you, discussing each of their demands. Some organizations also then ask each party to remove one of their demands, in the presence of the other co-worker, leaving the remaining 8 in the Contract. This would bode humility and additional "willingness" to work together. Once the final 8 have been determined, as the leader, you would both ask the individuals to sign the document and provide each with a copy. It might also be helpful to state that you will be placing a copy in each of their files. This again denotes the fact that it is the business requiring the agreement and not merely their manager. If necessary, you could also state you'd like to hold a 60 day follow up meeting to review progress of their partnership.
One final note, it has been my experience that these types of relationships affect non-departmental employees, in addition to the members on your team. Word travels fast and it can end up hurting your team's overall productivity and their political ability to get their needs met through other departments. Depending on how visible these team members are within the organization, it also can affect your reputation as a leader if not careful. You will want to be viewed in control of these types of situations and that you possess solid leadership skills. From your wording in the question above, as well as your number of direct reports, I'm quite confident in your capabilities.