Has anyone had to allocate the space of a warehouse/3PL between different businesses/customers and have any methodology they can share?

It is pretty much the same logic where a 3PL allocates costs over different clients in a multiuser warehouse; If the operations dynamics are similar, share of warehouse space (by m2, m3, or pallet places) can be a good reference for sharing all costs. If throughput volume or value of the goods or avg. order sizes etc are dramatically different respective costs like labour, electricity etc. can be shared by using different ratios.

We do combination of both, also manage by different aisle dedicated to customers.

It depends on the nature of the allocation, how/if you plan to inventory the items in the space, & how/if you plan to relieve the inventory. We normally create a specific location in our system to allow us to digitally track the inventory while requiring everything has a part # to inventory. Each customer should be assigned a specific contact (an account rep or inventory personnel) that knows what location their customer’s inventory is in to be pulled from upon receiving an order.

Another methodology is utilizing a large customer order that will allocate the inventory without segregating it but requires manual maintenance by reducing order qty as another firm order comes in. This method also would benefit from an account rep responsible for managing the orders.

I’m sure there are other more efficient ways to do this within an ERP but unfortunately I have not found them yet within ours.