Definition Drift in Hotel Performance Measurement: A Practitioner Framework for KPI Comparability and Decision Safety

Hotel performance management depends heavily on ratios, departmental statements, benchmarks, and comparative commentary. Yet a mathematically correct KPI can support an unsafe management conclusion when the underlying definition, classification, allocation, mapping, timing, or denominator has changed. This paper proposes the practitioner concept of definition drift: a loss of comparability created when a reported measure retains a familiar label while its underlying construction changes. The paper develops a four-part Definition Check Card—Content, Continuity, Movement, and Decision—to help hotel managers separate genuine operating movement from reporting-basis movement before assigning causes or actions. The framework is illustrated using hotel-specific examples involving average daily rate (ADR), restaurant average check, labor visibility, and food-and-beverage cost mapping. A synthetic ADR example demonstrates that reported ADR can rise from $150 to $180 with no change in room price, rooms sold, or guest cash when a $30 destination-style fee is moved into the Rooms Revenue numerator. The paper argues that common reporting frameworks such as USALI materially improve comparability, but do not eliminate local policy, system mapping, operating-model, and denominator differences. The practical implication is a disciplined review sequence: open the number, compare the basis, separate operating from definition movement, normalize or caveat the comparison, and only then act. The framework is intended as a decision-safety control for hotel finance teams, general managers, department heads, analysts, owners, and asset managers, and as a basis for future empirical testing of comparability failures in hotel performance measurement. Series: eHMS Hospitality Finance & Management Practice PapersWorking Paper: No. 001Author: Manish GuptaPublished by: eHMS Press / eHotel Management School