<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
            targetNamespace="http://example.org/ord"
            xmlns="http://example.org/ord"
            xmlns:prod="http://example.org/prod">

  <xs:import namespace="http://example.org/prod"/>

  <xs:element name="order" type="OrderType"/>
  <xs:complexType name="OrderType">
    <xs:sequence>
      <xs:element name="items" type="ItemsType"/>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="ItemsType">
    <xs:sequence>
      <xs:element ref="prod:product" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>


</xs:schema>