Based on a recent post on yahoo forums, seems like there may still be confusion out there as to what the differences are between these two roles. Questions like, is there overlap? can the Product Manager take on the responsibilities of the Product Owner? what are the specific requirements for either role? pop up all the time.
There was a really good discussion on the Scrum Development Yahoo group on this topic and some really good points were made. So I'll try to distill this for you here and of course put my own twist on this.
I think that the founders of Scrum purposely chose a different title for a reason. They could have easily just kept the title the same. But I think there was good reason for this. And that is that the PO has a specific set of duties in the Scrum role.
How do their roles differ?
First and foremost is that the PO drives the priorities for the development team. This is done via the Product Backlog as a vehicle for communicating priorities. Essentially, a company has a certain available capacity to turn requirements into working functioning code. How that capacity is used up is completely in the hands of the PO.
In order for the PO to do this, the PO needs to understand the bigger picture. Whether or not the PO distills this information from other roles or whether he has to get this information himself depends on the company.
Based on his/her understanding of the bigger picture, there are some additional specific duties that the PO must perform (not necessarily defined anywhere):
1. Articulate the product vision to the team
2. Define the goals at the beginning of every sprint
3. Tell the story behind each user story so that the development team understands what is required. So the PO must understand the end user requirements.
4. Define or help define the user story acceptance criteria so the team knows when they are DONE
5. Be able to prioritize the stories and be able to negotiate/collaborate on priorities with the team. Negotiate priorities occurs when after taking the top priorities off the backlog; there may be some remaining capacity that the next highest priority story won't fit in to. So in those cases, a lower priority feature could be picked.
6. Must be available at all inspect and adapt points to answer questions and help guide the team empirically
Product Managers on the other hand must be able to do a whole bunch of other things, including but not limited to:
1. Defining the marketing strategies and outbound marketing communications
2. Pricing strategies
3. Understanding the positioning of the product in the market place
4. Competitive analysis
A couple quotes from the forum worth repeating here
"Scrum does not prescribe further responsibility beyond optimizing development to ensure business success" (Anonymous)
"The Product Owner role, on the other hand, is really about representing the business side and working with engineering to optimize the software (or technology) delivery part of the entire product solution." (Greg)
The best ..
"The product owner role is a genuinely new role and disruptive for most organisations, as it does not easily map onto existing roles and structures" (Roman)
In summary, depending on your situation, the PM and PO roles will be performed by the same person, a group of people or separate people - frankly I don't care. As long as there is a person dedicated to doing the PO duties and responsibilities as defined in the 6 bullets above, then all is good from a scrum perspective.