When a customer requirement (quote or an order) comes, we use the stock status window to check what's available for the item. However, there should be a "On Hold Qty" field, just like the on hand, in production, allocated, etc... to show visibility of a job that may be fulfilled for this new requirement. This of course all depends on what the hold actually is.. but it gives the planner or the person assessing the customer requirement the chance to look into it...