I work in a small team (~5 people) and I am trying to encourage the team to adopt a more robust project management process. To date, our process has been rather 'ad hoc' and we have had failed attempts at Scrum.
One of the biggest problems I face (whether in Scrum or not) is that roles are not clearly defined, and I cannot get the support from the team to do this. Whereas I want a single person (the product owner) to be responsible for setting priorities (taking input from the rest of the team), the product owner is keen to make the entire team responsible for priorities.
I have tried to make the argument that this 'dilution of responsibility' undermines his role and has a negative effect on the project. As it is, no team member has a clear idea of the priorities over the next week, and team members are often taken off tasks randomly as 'priorities change'.
How can I best tackle dilution of responsibility?