The guest effectively places the order with the cook. The host communicates this
order to the clerk, who places the order with the cook. The phone system provides
the physical means for the order to be transported from host to clerk. The cook gives
the pizza to the clerk with the order form (acting as a “header” to the pizza). The
clerk boxes the pizza with the delivery address, and the delivery van encloses all of
the orders to be delivered. The road provides the physical path for the delivery