PTO and ATO or Different Ordering Environments,

PTO is Pick To Order: where it is assumed that

availability of stock is plenty , just pick and relese and ship for an order.

ATO is Assemble to Order : it is assuemed that,

availble of option class, all included/standard items/ and depending up on the Order the Assemblies are carried and shipped.

where it is expected that an order is booked for a predefined model item,