One of the benefits of agile, at least in theory, is the single product owner. In conventional projects we can have many people in the position of the product sponsor or product owner.  These multiple voices can provide contradictions in which our product development team must wade through to determine the real requirements.  Experience indicates this is one of the reasons conventional projects often run afoul of the schedule.

Communications channels grow as we add team members and that goes for product sponsors or in the case of agile product owners.  The equation goes:

Number of Communications Channels = [N(N-1)] 2

To demonstrate this complexity, we provide a graph of this function:

Relationship between the umber of people and communications channels.

As we add people that require special communications handling, we increase the amount of management required.  In the case of a collocated agile team, scrum master and a single product owner, we can perhaps approximate this as 3 entities.  The team is certainly not a single homogeneous entity; however the team is in one location and they are having daily group conversations that include the daily sprint meeting.

It can be argued that a source of project failures is due to the often long communications chains and uncertainty.  Adding multiple product owners adds to our communications challenges eroding one of the benefits of agile.  If we have multiple product owners, it is sound advice to use some type of stakeholder identification chart, and clearly articulate the expectations and areas of contribution of each product owner as best possible.

As a note, Value Transformation is constructing and online agile course at our online site at https://valuetransform.com/training/login/index.php