Three events demarcate these activities: order placement,
order shipment, and order receipt. Order placement
by the customer is the event that triggers the sourcing
activity. In the order placement phase, customer purchase
information is transmitted by the online retailer to a
particular supplier. Once it is received, the supplier
matches the demand by issuing a request for the item(s)
to be sourced from its inventory locations for shipment to
the customer-specified location. Delays can occur when
the supplier does not hold adequate inventory in stock and
must reach up its supply chain to alternative distribution
points or to the manufacturing sources.