Allocate Inventory over time, taking into account future incoming goods

[diederik]

Hi, we are looking for a way to allocate our inventory and incoming goods to our open sales orders in current and future time. The goal is to know per week how much inventory is available for new sales orders, taking into account that future sales orders have already been confirmed and we have a lead time of 15 weeks for new products. Below an example with a manual calculation, Howvever we would like to make this in a formula.

I really hope somebody can point us in the right direction.