Two covering plans
Option A has a larger margin but costs more; Option B is cheaper with less headroom. The decision belongs to the value of flexibility and risk tolerance.
Education
Compare two named classroom plans by usable seats, margin, utilization, and annual cost
Both options face the same enrollment. Resolve whether each plan covers the cohort first, then compare the cost and capacity margin without collapsing them into one vague winner.
CAPACITY SCENARIO COMPARISON
Compare two named classroom plans by usable seats, margin, utilization, and annual cost
Both options face the same enrollment. Resolve whether each plan covers the cohort first, then compare the cost and capacity margin without collapsing them into one vague winner.
Stronger seat margin-
Lower annual cost-
Option A usable seats-
Option B usable seats-
Option A cost / usable seat-
Option B cost / usable seat-
LIVE CAPACITY / SCORE VISUAL
Read the current value beside the exact ledger
Both options face the same enrollment. Resolve whether each plan covers the cohort first, then compare the cost and capacity margin without collapsing them into one vague winner. The visual updates from the same validated calculation record; it is an interpretation aid, not a policy or compliance ruling.
| Metric | Baseline | Option A | Option B | Decision boundary |
|---|
How to use
Compare named options against one shared enrollment
- Enter the shared enrollment and the baseline capacity used for context.
- Describe Option A and Option B with room count, seats, reserve, and annual cost.
- Check each option’s usable seats and margin before considering cost.
- Use cost per added usable seat only as a secondary efficiency measure.
- Record why the chosen option is acceptable beyond the arithmetic comparison.
Scenario fundamentals
A scenario comparison keeps the choice and the boundary visible
- Shared enrollment
- The same demand applied to both options.
- Usable seats
- Rooms times seats after each option’s reserve.
- Seat margin
- Usable seats less shared enrollment.
- Coverage state
- Whether the option covers enrollment without a modeled shortfall.
- Added-seat cost
- Annual cost divided by usable seats above the baseline.
Calculation method
Resolve capacity coverage before ranking cost
Each option is calculated independently with its own reserve. The comparison retains baseline usable seats, option margins, utilization, and annual cost. The lower-cost option is not automatically the stronger capacity choice if it leaves a shortfall or depends on a different service assumption.
Fair comparison
Keep the demand and reserve logic common where they should be common
Both options use the same enrollment. If one option serves a different programme, has a different timetable, or has a different reserve rationale, document that difference instead of treating the numbers as perfectly interchangeable.
Cost interpretation
Cost per seat is not a quality score
Cost per added seat is an efficiency ratio based on entered annual cost and added capacity. Accessibility, travel distance, staffing, maintenance, and programme fit may dominate the real decision.
Visual reading
Use the grouped bars to see coverage, not just scale
The chart places baseline, Option A, and Option B beside the same enrollment series. The table provides exact margins and costs; the visual should be read as a quick coverage comparison.
Detailed calculation process
Option equations and default substitution
Usableⱼ = roomsⱼ × seatsⱼ × (1 − reserveⱼ ÷ 100)Marginⱼ = usableⱼ − enrollmentUtilizationⱼ = enrollment ÷ usableⱼCost per added seatⱼ = annual costⱼ ÷ max(usableⱼ − baseline, 1)
- Defaults: enrollment 480; baseline 16×28 at 8%; A 18×28 at 8% and $145,000; B 17×30 at 12% and $128,000.
- Baseline usable = 16×28×0.92 = 412.16 seats.
- Option A usable = 18×28×0.92 = 463.68; margin = −16.32 seats.
- Option B usable = 17×30×0.88 = 448.80; margin = −31.20 seats.
- Both options have a shortfall in this default record, so cost ranking is not a coverage approval.
- The ledger and PDF retain the negative margins and the cost-per-added-seat basis.
The current scenario comparison above provides the final reconciliation.
Result interpretation
Negative margin is a first-order finding
A scenario with negative margin should be reviewed before its annual cost is called efficient. If both options cover demand, the stronger margin and lower cost answer different questions and may point to different choices.
Decision review
Ask what the option is buying
More rooms may buy scheduling flexibility; more seats per room may buy density. Keep the service and programme consequence beside the arithmetic result.
Limits and exclusions
Scenario exclusions
- No construction, lease, transport, maintenance, or staffing cost beyond annual cost entered.
- No difference in room quality, accessibility, programme type, or timetable complexity.
- No probabilistic enrollment uncertainty or multi-year escalation.
- No automatic winner when one or both options have a shortfall.
Key terminology
Comparison vocabulary
- Option
- A named configuration with its own inputs.
- Baseline
- The reference capacity before the options.
- Margin
- Usable seats less shared enrollment.
- Coverage
- The condition where usable seats meet demand.
- Utilization
- Demand divided by usable capacity.
- Added-seat cost
- Cost divided by capacity beyond baseline.
Worked decision cases
Two options that should not be collapsed into one score
One covering plan
When Option A covers and Option B does not, the cheaper B cost cannot override the coverage boundary without an explicit change to enrollment or reserve policy.
Authoritative basis
Sources for capacity comparisons
Important note
Use the comparison to frame a decision. Local programme rules, building standards, budgets, and staffing commitments remain outside this arithmetic.
Frequently asked questions
Why is enrollment shared?
A fair capacity comparison applies the same demand to both options.
What does a negative margin mean?
The option does not cover the entered enrollment after reserve.
Why compare cost per added seat?
It exposes a secondary efficiency ratio above the baseline.
Can a cheaper option still lose?
Yes, if it fails coverage or has unacceptable operating consequences.
Does the page account for inflation?
No; annual cost is the entered comparable basis.