Add a row per top-level part you plan to build and how many. This explodes recursively through the BOM to every component.

Each component's requirement is netted against on-hand inventory and quantity already on open POs — only the shortfall shows as a real requirement.

Order now means the vendor's lead time won't make your need date (or none is known); order soon means there's still time; ok means no shortfall.

Select rows with a suggested quantity and a known vendor, then click Create POs — one draft PO per vendor, grouped automatically.