The Product Owner role in Scrum is a well-defined description of how a single person who represents the business interacts with a Scrum team to get software or products implemented that the business wants or needs.
This is in no way a complete description of what the business has to do to reach that point, nor is it intended to be. But too many Scrum teams think that the description of Product Owner is a complete description of the business role and do not recognize why the person they think should be in the role is seldom the right person.
So what does “the business” do? First, we have to identify what “the business” means. In this context “the business” is how the company makes money. It can be for example a product, product family, business line, or service unit. Sometimes “the business” is an internal unit of the company, such as accounting, that supplies necessary services to the corporation. Someone is responsible for that business, typically someone who is reporting directly to the CEO or COO of the company.
What is that business owner responsible for? This person is responsible for knowing everything that could impact business including the market, the users, the regulatory environment, and the competition. This is the person who decides when to pivot, what to do about disruptive technology, when to enhance a product, or when to remove a product from the market. The business owner makes suggestions to the C-executives about budgets and is responsible for the Return on Investment (ROI) for their business. For overhead units (those that do not make money), the business owner is responsible for providing the services in the most cost-effective manner.
Unless the business is tiny, this is not a job for one person. The ultimate business owner has a team of people who work to collect information, create reports, suggest work to be done, suggest budgets and so on. The staff working for the business owners are experts in their own areas. All of this information is reviewed by the business owner and is the input to his or her own decision making processes.
While the business owner is ultimately responsible for the business, this person is rarely involved in the details of the work to run the business. That is why they have staff to do that work. For any particular project that needs to be done, it is seldom the case that the business owner is the one who knows the details of that work, and so that person makes a poor choice to be Product Owner to the Scrum team. Yes, this person is ultimately responsible for the vision and return on investment of the business, but that does not mean the business owner wants or needs to be responsible for the vision and return on investment of a particular initiative, nor do they have the time to do so.
So who will take on the Product Owner role for the duration of a particular initiative? The person who is the Product Owner will be someone who has the knowledge of what needs to be done and the trust of the ultimate business owner to deliver the required ROI. This person is trusted to balance the needs of the users, the needs of the business, and what is technically possible in order to achieve the best overall result.
While the Product Owner will usually be able to make the day-to-day decisions, there may be times when he or she needs to discuss questions with the ultimate business owner. Some complex situations may be beyond the ability of any one person to handle, and so the person who is the Product Owner may sometimes need to get a team of people together to work out the best thing to do. This should never be because the person with the Product Owner role is too junior, but should be due to the size or complexity of the work.
Business owners make a big mistake when assigning very junior people to the Product Owner role. This is a role for a person with deep knowledge and understanding of the business vision and the market (or of a specific supporting domain such as accounting), and the the ability to deliver on the required ROI. People like this are very valuable to the business and cannot be converted to Product Owner as their full-time job. Instead, they should be assigned to a specific initiative which they are best suited to guide. The work of Product Owner should take only part of their time, since they need to also spend time continuing to keep track of what may be changing that impacts their business and the specific initiative they are guiding as Product Owner.
For business units that make money for the company, the Product Owner will often have job titles such as Product Manager, Marketing Engineer, Marketing Visionary, Business Analyst (on the business side, not from IT), Solution Anthropologist, User Experience expert, and possibly even Head of Sales. For overhead departments you might have a Lead Accountant, Statistician, Big Data Guru, Lawyer, Operations Manager, or Head of Customer Support.
Scrum teams should always keep in mind that to get someone with the knowledge and authority to be responsible for the vision and ROI, they will have Product Owners who have jobs that go far beyond the Product Owner role. The Product Owner role only describes the interaction of the business with the Scrum team, which should rarely be a full-time job (and then only for brief periods).