Manager cannot currently handle production orders with multiple inventory item outputs. So you will have to manually calculate how much of the input inventory item goes into each output inventory item.
Waste is ignored as an output. For example, if 100 kgs of input product produced 4 20-kg bags of output product, the missing 20 kgs is assumed to have been consumed in production. Its cost will be reflected in the cost of the 20-kg output bags. Your inventory quantities will decrease the input item by 100 kgs and increase the output item by 4.