The _shipping_total name/value pair on the OrderForm object stores the total cost of shipping for an order. Commerce Server version 3.0 supplies a number of components that you can use to compute the value to be stored in this name/value pair.
The DefaultShipping component sets this name/value pair to zero (0). If you do not want to charge shipping on an order, you can include this component alone in the stage.
Multiple components can be specified to allow for different shipping costs depending upon the shipping carrier used. Because you cannot anticipate which carrier your customer will select, you anticipate either situation in your pipeline.
Suppose, for example, that you offer customers the option of shipping by either UPS or Federal Express, and that you charge $19.95 to ship by one of these carriers and $29.95 to ship by the other. To configure the Shipping stage to handle this situation, include two instances of the FixedShipping component in your pipeline. One instance would be configured to apply the shipping cost to the OrderForm's _shipping_total name/value pair where the _shipping_method is equal to UPS, and the other would apply a different shipping cost to the _shipping_total name/value pair where the _shipping_method is FEDEX.