staffing-to-ratio-scheduling

# Staffing to Ratio Scheduling Staffing to ratio is where **compliance and the cost model meet**. Labor is the dominant cost in a center, and it does not slide smoothly — it **steps up a whole teacher** each time a room crosses a ratio boundary. Ratios are state-specific and `[verify-at-use]`. ## The loop 1. **Model labor as a step function.** For each age group, the required ratio sets how many children one teacher covers. Adding the child that crosses the boundary adds a whole teacher's cost, not a fraction — see the staff-a-room-to-ratio tree in [`../../knowledge/childcare-decision-trees.md`](../../knowledge/childcare-decision-trees.md). 2. **Cover the whole day in ratio.** Ratio must hold at open, at close, and through breaks and nap transitions — the schedule, not just the roster, must never dip below ratio. Openers/closers and float coverage are part of the model. 3. **Only count ratio-countable staff.** Qualified, verified adults count toward ratio; others don't — coordinate with [`../ratios-and-licensing-compliance/SKILL.md`](../ratios-and-licensing-compliance/SKILL.md) so the schedule's headcount is the *compliant* headcount. 4. **Read cost per room against revenue.** Compute the ratio-driven labor cost of each room and compare it to the room's tuition revenue at current enrollment. A partly-filled room can be underwater because the teacher is fixed while the tuition scales with enrolled children. 5. **Fill toward the next boundary, deliberately.** A room just over a boundary (one extra child forcing a second teacher) is the least efficient state — fill it toward full or don't cross the boundary. That capacity-and-margin call is `childcare-center-lead`'s. ## Metrics | Metric | Reads | Note | |---|---|---| | Ratio-driven labor cost / room | teachers required × cost | The step function, per room | | Revenue per enrolled child / room | tuition ÷ enrolled | Compare to the labor step | | Enrollment vs ratio boundary | children to next teacher | Just-over-boundary = least efficient | | Coverage-in-ratio all day | open/close/breaks held | Schedule, not roster | ## Anti-patterns - Averaging labor cost instead of modeling the whole-teacher step. - Scheduling to ratio at midday but dropping below it at open/close or breaks. - Counting non-ratio-countable adults to hit a number. - Running a room one child over a boundary indefinitely. ## See also - [`../ratios-and-licensing-compliance/SKILL.md`](../ratios-and-licensing-compliance/SKILL.md), [`../../templates/ratio-staffing-plan.md`](../../templates/ratio-staffing-plan.md). - Best practices: [`../../best-practices/staff-to-ratio-is-the-cost-model.md`](../../best-practices/staff-to-ratio-is-the-cost-model.md), [`../../best-practices/ratios-are-a-floor-not-a-target.md`](../../best-practices/ratios-are-a-floor-not-a-target.md).