As infrastructure and operations (I&O) organizations move to digital product teams, it’s becoming increasingly ineffective to base governance on traditional controls (processes, manual inspection, and stage-gated approvals). A new approach — based on a digital-era theory — is to ensure that teams document their promises, which then serve as a basis for governance, audit, and related assurance activities. This report introduces promise theory and provides guidance on how to implement it in an agile environment.