Option Overplanning
Definition
Option overplanning is the practice of deliberately planning option modules to a higher percentage than the expected mix — for example planning 45% for an option forecast at 40% — so mix variability doesn't cause shortages in assemble-to-order production.
In Practice
In assemble-to-order planning, total volume may be forecast well while the option mix swings: trucks might be 40% engine A on average but 30–50% in any given month. Overplanning inflates the option percentages on the planning BOM above 100% in total — say 45% engine A, 40% engine B, 25% engine C — creating buffer coverage of the components unique to each option.
It is effectively safety stock expressed at the option level, positioned exactly where mix uncertainty bites while the common parts are planned at 100% with no duplication. The extra percentages should reflect each option's mix variability, and the master scheduler consumes the overplanned quantities as actual orders arrive, letting unconsumed buffer roll or wash out.
Frequently Asked Questions
Why do option percentages exceed 100% in overplanning?
Because each option's percentage is padded against mix swings: engines forecast at 40/35/25 might be planned at 45/40/30, totaling 115%. The extra 15% buffers the option-specific components. Total product volume stays at 100% — only the mix-sensitive modules carry the hedge.
How much should each option be overplanned?
In proportion to its mix variability and the cost of its unique components. An option whose share swings ±10 points needs more buffer than one that is stable, while expensive or long-lead option modules justify more careful statistical sizing. Review actual mix distributions rather than applying one flat uplift.
Related Calculators
Related Terms
A planning bill of material is an artificial BOM that groups items for forecasting rather than building — typically a product family parent whose components are options and common parts weighted by their expected percentage of total demand.
Modular Bill of MaterialA modular bill of material organizes a configurable product into option modules — such as engines, cabs, and transmissions — so any customer configuration can be built by combining modules instead of maintaining a BOM for every possible variant.
Super Bill of MaterialA super bill of material is a planning BOM whose parent is an artificial family item and whose components are the option modules and common-parts groups that make up the family, each carried at its forecast percentage of total demand.
Safety StockExtra inventory held beyond expected demand to protect against variability in demand or supply. It acts as a buffer that keeps orders flowing when forecasts miss or deliveries run late.