gop auto schedule rest api payload, how intrasit lead time will calculated for arrival and ship date

we are implementing supply chain planning cloud module. order management wil be ebs. we are using GOP Auto schedule rest api payload, payload we are passing customer name and customer party site number, ship method. ship method set for region wise or zone wise. How transit lead time will be calculated. What is logic behind Cloud.
if you have sql query please share us or how your checking based on customer party site number and ship method in cloud.