The Scrum product owner is typically a project's key stakeholder. Part of the product owner responsibilities is to have a vision of what he or she wishes to build, and convey that vision to the scrum team. This is key to successfully starting any agile software development project. The agile product owner does this in part through the product backlog, which is a prioritized features list for the product.
The product owner is commonly a lead user of the system or someone from marketing, product management or anyone with a solid understanding of users, the market place, the competition and of future trends for the domain or type of system being developed.
This, of course, varies tremendously based on whether the team is developing commercial software, software for internal use, hardware or some other type of product. The key is that the person in the product owner role needs to have a vision for what is to be built.
Although the agile PO prioritizes the product backlog during the sprint planning meeting, the team selects the amount of work they believe they can do during each sprint, and how many sprints will be required.
The product owner does not get to say, "We have four sprints left, therefore you must do one-fourth of the product backlog this sprint." The Scrum product owner's job is to motivate the team with a clear, elevating goal. Team members know best what they are capable of, and so they select which user stories from the top of the product backlog they can commit to delivering during any sprint.
In return for the Scrum team's commitment to completing the selected user stories from the top of the product backlog, the product owner makes a reciprocal commitment to not throw new requirements at the team during the sprint. Requirements are allowed to change (and change is encouraged) but only outside the sprint. Once the team starts on a sprint, it remains maniacally focused on the goal of that sprint.
The product owner role requires an individual with certain skills and traits, including availability, business savvy and communication skills. First, the Scrum product owner needs to be available to his or her team. The best product owners show commitment by doing whatever is necessary to build the best product possible – and that means being actively engaged with their teams.
Business savvy is important for the agile product owner because he or she is the decision maker regarding what features the product will have. That means, the agile PO should understand the market, the customer and the business in order to make sound decisions.
Finally, communication is a large part of the product owner responsibilities. The product owner role requires working closely with key stakeholders througout the organization and beyond, so he or she must be able to communicate different messages to different people about the project at any given time.