treatment-room-and-injector-utilization

name	treatment-room-and-injector-utilization
description	Read a med spa on its two scarce inventories — injector-hours and treatment-room-hours. Utilization = productive hours booked / available, read by provider and by room and by daypart; confirm the current capacity is full before adding an injector, a room, or a device.

Treatment-Room & Injector Utilization

A med spa is a stack of injector-hours and treatment-room-hours, and the injector is usually the binding constraint. Both are perishable — an hour that goes empty cannot be resold tomorrow. This skill reads utilization before the practice spends on capacity.

The loop

1. Compute utilization two ways. Injector/provider utilization (productive hours booked / available) and room utilization. The lower of the two is the real constraint; adding the other does nothing. Benchmarks are [verify-at-use].
2. Read it by daypart. A book that's full Saturday and empty Tuesday is a demand-shaping problem (see pricing/membership), not a capacity one.
3. Separate revenue from busy-ness. Revenue per available injector-hour and per room-hour catch the full-but-low-contribution book that a headcount view misses.
4. Test the constraint before adding capacity. Don't add an injector, a room, or a device until the current scarce resource runs full at peak. A half-full book is a fill problem.
5. Feed the device decision. A capital device consumes room-hours; its payback (see below) must clear the value of the room-hours it displaces. Hand the payback model to med-spa-operations-lead.

Metrics

Metric	Reads	Note
Injector utilization	productive hrs booked / available	Usually the binding constraint; [verify-at-use] on norms
Room utilization	productive room-hrs booked / available	The other half; the lower one binds
Revenue per available injector-hour	service revenue / injector-hours	Catches full-but-low-contribution books
Peak vs off-peak fill	daypart utilization spread	Demand-shaping signal
Device utilization (if applicable)	device treatment-hrs / available	The payback denominator

Anti-patterns

• Adding an injector or a device to fix what is a fill-rate problem.
• Reading a single blended utilization number that hides the binding constraint.
• Buying a device on the vendor's full-utilization payback instead of the practice's realistic volume.
• Ignoring the empty daypart because the peak is full.

See also

• ../service-mix-injectables-devices-memberships/SKILL.md — mix and device payback ride on these hours.
• Best practices: ../../best-practices/injectables-are-perishable-provider-hours.md.
• Command: /model-device-payback.