In an Agile environment, where there are multiple Scrum teams, I'm told that each team can nominate an "ambassador" to represent them in the "Scrum of Scrums" stand-up.
What happens when there is conflict (priorities, dependencies, technical standards etc.) between 2 or more teams?
How do the multiple teams maintain a co-ordinated direction when different team members may attend the SoS each time? Is there an overall product owner?
The Scrum of Scrums should happen after the daily Scrums because otherwise it would be hard to answer the three questions there. In case there is an important decision, the ambassador shall go back to the team, and explain in 3-5 minutes.
Anybody from the team shall be able to represent the team in the SoS because they pay attention during their Scrum. Usually, teams send the Scrum Master to these meetings, but this is just customary.
It is a good thing if the POs can join the SoS because that is a good start to solve problems, but at least the overall PO should be present.
What happens when there is conflict (priorities, dependencies, technical standards etc.) between 2 or more teams?
That's what a SoS meeting is for - not necessarily to resolve the conflicts, but to identify them and coordinate and facilitate the resolution.
How do the multiple teams maintain a co-ordinated direction when different team members may attend the SoS each time?
Typically it's the same person each time, usually the scrum master from each team. Sending the same person tends to work better as the SoS group learn how to work well together.
Is there an overall product owner?
Depends if there is an overarching product/portfolio. SoS can be used as a way of scaling agile, in which case there will often be a Portfolio Owner/Manager (who is responsible for multiple Products). But in other instances SoS is just used as a way to coordinate multiple loosely coupled products (and in that instance they may each have their own PO but no Portfolio Owner).
I don't know what the accepted approach is but I've always implemented this by having the SM from each team attend the Scrum of Scrums.
We have it where the SM and PO attend the meeting. The frequency is once a week. Focus should be on identifying blockers and inter team dependencies. We typically start by reviewing the Iteration Backlog and check if the remaining stories can be completed in the left over time and what stories may spillover & their impact. Each Scrum Master then gives an overview of what is done, planned and blocked.
