I have a model where I use date-time source (Source - Orders) to generate demand for each SCs (queues). Then I accordingly pull item from list each part (token) takes a particularly processor to reaching respective SC. If a particular item is unavailable then an item is created in Queue5 and sent to respective SC. I want to track time from order creation (demand generated in Source - Orders) to order delivery (reach at SC). I don't want to track total part time in system because the part may already exist before demand was generated. I want to do this because the processing times vary via distributions. I want to able to do this for all SC (track order delivery time).