<p>The hairdressing industry represents a materially under-researched sector within revenue management literature, despite exhibiting all core characteristics of a perishable inventory environment. Hair salons operate under fixed and time-constrained capacity, segmented demand, variable service durations, skill-dependent productivity, and contribution margin variation at the service level. These characteristics closely resemble those found in restaurants, airlines, and accommodation, yet formal revenue management (RM) frameworks have not been systematically applied or adapted to this sector. This paper introduces a time-based inventory framework for hair salons, proposing the use of seat-minutes as the baseline unit of capacity measurement. It extends traditional RM metrics by introducing seat-minute occupancy, average revenue per booked seat-minute, revenue per available seat-minute (RevPASM), and a seat utilization ratio adapted to the salon context. The paper further examines the role of stylist skill as a capacity efficiency modifier, demonstrating how variations in service speed directly affect effective capacity and revenue potential. By framing salons as time-based inventory systems rather than chair-based businesses, this paper provides practitioners and researchers with a structured analytical foundation for inventory and profit optimization, pricing discipline, and capacity control in personal services. While developed using hair salons as the primary analytical case, the framework is transferable to adjacent beauty services where time, skill, and fixed service capacity constrain revenue generation.</p>