This retrospective operational case examines beverage performance within a high-volume four-star hotel Food & Beverage environment and reconstructs the intervention through the lens of Decision Architecture™. The case documents changes in stock visibility, assortment management, cocktail costing, wine-pairing activation, product display and staff execution, alongside a documented +4–6% improvement in beverage margin and the elimination of residual beverage stock at the end of the operating period. The purpose of the case is not to establish that Decision Architecture™ independently caused the reported financial improvement. The framework had not yet been formally defined when the original intervention occurred. Instead, the case applies the Decision Architecture™ Diagnostic Framework retrospectively to analyse relationships between operational signals, decision triggers, decision authority, execution, feedback, learning and adaptation. The case therefore serves as an empirical exposure of the framework to operational reality and highlights the need for future prospective measurement of signal time, trigger recognition, decision time, action time, outcome review and adaptation.