There can easily be multiple user organizations on a project or program.
A user organization and other organizations may belong
either to the same or to different businesses.
Like the same person playing multiple roles or being a
member of multiple teams, the same business division may be
modeled as a user organization as well as a:
Development organization if it develops work products it users.
Customer organization if it funds the development of the work products it uses.
Operations organization if it operates the applications it uses.
Maintenance organization if it maintains the work products it uses.