This document provides an overview of available to promise (ATP) in SAP-SD. It discusses what ATP is, how to view the ATP situation using transaction CO09, and how the system arrives at a confirmed delivery date using backward and forward scheduling based on availability. It also outlines the key dates, times, and configurations needed for ATP checks, including requirements type, class, strategy group, checking group, rule, and scope. ATP projections are based on defined rules and are not the actual stock situation.