What exactly is a BIAN Service Domain?

A BIAN Service Domain is a conceptual design of a discrete business capability. Its scope is defined to be ‘elemental’ meaning that if it is broken down any further the components lose their unique business context and become utility in nature. They perform their associated business function for the full life cycle for all occurrences and are specifically designed to support service enabled supporting system solutions. See the Practitioner´s Guide for more details