Forecast accuracy is an input, not the Supply Chain decision
Better forecasts do not automatically produce better purchasing, inventory, allocation or production decisions.
Joannes Vermorel argues that improving forecast accuracy does not automatically determine what to buy, where to allocate inventory, which capacity to reserve or which customer to prioritise.
The affected decision is how limited inventory, capacity and cash are allocated under uncertainty. Value requires the forecast to be converted into an explicit decision objective that includes lead times, minimum order quantities, supplier reliability, shelf life and economic consequences.
The principal failure mode is improving forecast metrics while purchasing and allocation rules continue producing stockouts, excess inventory and manual firefighting.