Order to cash refers to the business process in which customer sales orders are accepted by a manufacture, fulfillment of the order followed by shipping and receiving followed by the generating of an invoice and collecting payment for that invoice.

Buyer orders products from Seller. Seller accepts Order and confirms order fulfillment. Seller sends Advanced Shipment Notification to buyer as soon as products leave the Seller. Seller sends Invoice to Buyer. 

Buyer orders products from Seller, Buyer may or may not place change order. Seller may confirm all line items in the Purchase Order Confirmation or uses Purchase Order Update to confirm pending line items. Seller will send out Advanced Shipment Notification to Buyer. Seller will send out Invoice to Buyer. Buyer pays invoice. 

The process involves three trading partner, the Buyer, the Seller and the Logistic Service Provider.