Open-to-buy Planner methodology

grossNeed = planned sales + markdowns + ending inventory − beginning inventory

netOpenToBuy = gross need − on-order commitments + cancellations

overcommittedAmount = maximum of zero and negative net open-to-buy

overcommitted = net open-to-buy is below zero

Money inputs and outputs use the currency selected in the scenario without changing the canonical methodology. Rates, margins, utilisation and buffers are entered as percentages and converted to decimal values for calculation.

• All inputs must be finite and remain inside the visible validation boundaries.
• Whole-unit and whole-day fields reject fractional values.
• Percentages remain inside the closed range from 0% to 100%.
• Invalid denominators return an explicit unavailable result or fail closed; NaN and Infinity are never displayed.
• All six plan values must use the declared retail or cost basis; the engine performs no basis conversion.

Valuation basis minimum

basis ≥ 0 inventory valuation-basis selection — A lower value is rejected before calculation.

Valuation basis maximum

basis ≤ 1 inventory valuation-basis selection — A higher value is rejected before calculation.

Planned sales minimum

plannedSales ≥ 0 currency units/planning period on selected valuation basis — A lower value is rejected before calculation.

Planned sales maximum

plannedSales ≤ 10,000,000 currency units/planning period on selected valuation basis — A higher value is rejected before calculation.

Planned markdowns minimum

plannedMarkdowns ≥ 0 currency units/planning period on selected valuation basis — A lower value is rejected before calculation.

Planned markdowns maximum

plannedMarkdowns ≤ 10,000,000 currency units/planning period on selected valuation basis — A higher value is rejected before calculation.

Planned ending inventory minimum

plannedEndingInventory ≥ 0 currency units at planning-period end on selected valuation basis — A lower value is rejected before calculation.

Planned ending inventory maximum

plannedEndingInventory ≤ 10,000,000 currency units at planning-period end on selected valuation basis — A higher value is rejected before calculation.

Beginning inventory minimum

beginningInventory ≥ 0 currency units at planning-period start on selected valuation basis — A lower value is rejected before calculation.

Beginning inventory maximum

beginningInventory ≤ 10,000,000 currency units at planning-period start on selected valuation basis — A higher value is rejected before calculation.

On-order commitments minimum

onOrderCommitments ≥ 0 currency units committed for the planning period on selected valuation basis — A lower value is rejected before calculation.

On-order commitments maximum

onOrderCommitments ≤ 10,000,000 currency units committed for the planning period on selected valuation basis — A higher value is rejected before calculation.

Confirmed cancellations minimum

cancellations ≥ 0 currency units cancelled from planning-period commitments on selected valuation basis — A lower value is rejected before calculation.

Confirmed cancellations maximum

cancellations ≤ 10,000,000 currency units cancelled from planning-period commitments on selected valuation basis — A higher value is rejected before calculation.

• All inventory, sales, cost, target, capacity and cash values are supplied by the user.
• Money inputs use one consistent ex-tax currency basis and records refer to the same cohort or planning period.
• The engine retains raw precision; display formatting never feeds back into calculation.
• No jurisdiction, provider fee, industry benchmark or current policy value is embedded.

This planner has no current policy-data dependency. Its commercial assumptions are user supplied. Registered family-level regression suites exercise the shared business-logic engine and worked-result reconciliation.

• The planner does not convert between cost and retail valuation bases.
• Planned sales, markdowns and ending inventory are user scenarios, not forecasts.
• A positive open-to-buy amount does not prove supplier availability, cash availability or storage capacity.

This is educational decision support, not tax, accounting, legal or financial advice. Check the treatment of your actual transactions under the rules that apply to your business and seek qualified advice where appropriate.

Registered family-level suites test formula invariants and example reconciliation; the release ledger records that coverage without claiming a separate oracle for every line of public copy. There is no official threshold or benchmark to refresh for this planner. Commercial inputs remain user-supplied because they vary by business and contract.

1. 2026-07-16: Initial public release of the Open-to-buy planner and methodology.