Demand for Kanban

The kanban formula given in user guide is

(C - 1) * S = D * A * (L + SSD)

Where D is the avg demand
but from where system gets the value of D?

Oracle Applications Fusion Cloud - Inventory

Oracle Cloud/Fusion Manufacturing Cloud training will help you develop the fundamental skills required to set up and use the Manufacturing module. This training covers all the tasks, setups, forms and reports used in Manufacturing and related modules