PO-SO link

We have a scenario where we need to place a purchase order for some stock but we need that stock to be held/reserved for a specific customer.
We do not have a sales order from that customer for the stock.
But we have agreed to bring it in and hold if for them.

How can we mark that stock when it comes in so no one else can take it, but it is held at our usual warehouse.

Without actually recognising the demand no not really. All you can do is bring it into a segregated warehouse and have working practices telling users not to sell it. So you have agreed to buy it and all of the associated costs of storing and handling without any committment from the customer so it is really just your stock and you need to segregate it manually.

Thanks,

And what if we want to generate purchase order based on a sales order (i.e. purchase order created by systen due to demand by sales order)??

Functions - Direct Delivery (Drop Shipments)

Functions - Create Purchase Order