Huawei Huawei China Unicom CAICT This document defines a YANG module for SLA assurance management in optical transport networks. The module provides a standard way to define, detect, and report issues that may impact service and network availability. It enables consistent modeling of assurance intent, impairment detection, and risk reporting across optical transport domains. The YANG model is designed to support closed-loop operations, allowing automated monitoring, analysis, and remediation workflows to maintain high service reliability and SLA compliance