The allocations system is designed to pull inventory to selling locations based on projected demand, the allocation engine will pull the inventory needed down to the last unit of availability from the sources. In some scenarios, users may want to limit the amount of stock that leaves the warehouse in any given allocation.

This is usually applicable for initial allocations when allocators want to hold back an amount of inventory for unforeseen events. While this is typically not necessary in a demand driven allocation system, the allocator may know something that the system does not or may want to be cautious for certain products when allocating. Another reason may be to limit stock in stores to reserve it for web sales.

Regardless of the reason, users are able to set the holdback percentage on the allocation strategy and all available inventory will then be limited by that holdback percentage