Scaling SoS
There are development organizations that claim to have more than one product and more than one Product Owner in their Scrum of Scrums. Such a practice is not consistent with the basic principles of Scrum, that is, that multiple teams pull from the same Product Backlog and only one Product Owner can be responsible for the items included and their priorities.
As a basic rule, when you have multiple large products requiring multiple Scrum teams, create multiple Scrum of Scrums—with one SoS for each product. Each SoS has one Product Owner, one Product Backlog, and up to nine development teams. Still, large organizations often have products that are so large that a single Scrum of Scrums is not adequate to handle the organization's development objectives. Recall that an SoS is limited to no more than nine Scrum teams, each having no more than nine members. Ergo, a Scrum of Scrums can have no more than 81 people involved in development. So, what's the organization...