What ensures that a service provider and a service consumer continually co-create value?

A service relationship is defined as the cooperation between a service provider and service consumer. Service relationships are established between two or more organizations to co-create value. An organization can play the role of provider or consumer interchangeably, depending on the situation.

https://www.bmc.com/blogs/itil-key-concepts-service-management/#:~:text=and%20stakeholder%20management.-,Service%20Relationships,interchangeably%2C%20depending%20on%20the%20situation .