Draw your own supply chain.
Most brands have never seen their chain on one page. Put the nodes down, connect them, set the days on each leg, and the tool works out the longest path, which is your real lead time. Nothing is uploaded. It stays in your browser.
Put your chain on the table.
Add the nodes you actually use, connect them in the order stock moves, then click any leg to set its real number of days. The longest path is worked out as you go, and that is the figure your order-by dates hang off.
Your order-by date is this number, counted backwards.
Once you know the longest path, the date a decision is actually due stops being a feeling. Subtract it from the day a SKU runs dry and you have the day the order had to be placed, which is almost never the day it feels due.
Next PO placement = out-of-stock date minus total lead time. That is the whole thesis, and this map is the first half of it.
Bring the map to the call.
If you have drawn your chain and the total surprised you, that is the conversation. Thirty minutes, your numbers, and where the order-by dates actually sit.