I often hear from ScrumMasters and Agile Coaches stating, that you cannot have a succesful Scrum implementation without a Product Owner. The importance of the Product Owner can not be discussed, but there are “everyday situations” out there where a Product Owner for some reason is not available, as much as desired, and for sure won’t be for period of time. Telling the Product Owner to be more available won’t help anything, and calling off the desire of becoming more agile, doesn’t seem to be the solution as well.
Agile Reflections 