In Field Service we have Product Inventory which is a child of Product.
Product Inventory is based on Warehouses as below in an image from Neil Parkhurst blog.
I am trying to show in a Product view a Sum of all "Quantity On Hand" etc. With a rollup I only get the option to Count(Product Inventory) so would get a rollup field of 5 rather than a quantity on hand of 13.
Any ideas of how to rollup these columns without custom code?