Reading path for Product Owner
Traditional Agile organizations often combine the Product Owner and Product Manager roles into a single role that they call “Product Owner.” Lean-Agile divides these two roles to reduce complexity, enable proper focus on the market on the one side and proper focus on the product team on the other side, and to bring up conflicting interests that often get lost when the two roles are combined. In most circumstances we do not recommend a classic Agile Product Owner-only approach.
Traditional waterfall organizations will often add the responsibilities of the Product Owner to the Program/Project Manager (PgM) role. This is counter-productive.
The PgM role is already quite busy with monitoring, reporting, and other traditional program management tasks that do not include product ownership and advocacy. There is never enough “left-over” time available for a PgM to add Product Owner tasks and do them adequately.
The mindset is completely different: the PgM is typically taking a command and control perspective “over” the teams, while the Product Owner is operating within a peer perspective.
These and many other factors combine to make it counterproductive to combine the PgM and Product Owner roles.