implied promises tell the real story of a service
Services are rooted in promises, and there are always two sides to any promise. Anything meaningful within a service: outcomes, activities, tasks or resources etc, needs to be explored reflexively; seen from both sides of the handshake.
A promise is an undertaking or assurance given by one person to another, agreeing or guaranteeing to do or give something or not do or give something, in the future.
Services emerge from promises.