1. A computer program product comprising application software encoded on a tangible machine-readable information carrier, the application software being structured as process components interacting with each other through service interfaces, the software comprising: a plurality of process components, each of the process components being a package of software implementing a respective and distinct business process, the plurality of process components including: an Inbound Delivery Processing process component that combines tasks concerning inbound delivery processes and enables communication with a vendor and an invoicing process component; a Material Inspection Processing process component that provides services related to quality inspection; a Site Logistics Processing process component that supports preparation and execution tasks concerning internal inventory movement in a warehouse type environment; a Confirmation and Inventory process component that combines tasks required to confirm inventory changes; a Purchase Request Processing process component that provides a request or instruction to the purchasing department to purchase specified goods or services in specified quantities within a specified time; a Purchase Order Processing process component that includes a purchase order business object and a purchase order confirmation business object; a Purchasing Contract process component that handles an agreement between a purchaser and a supplier that details the supply of goods or the performance of services at agreed conditions; a Supplier Invoice Processing process component that includes a supplier invoice business object and a supplier invoice request business object; a Demand Forecast Processing process component that collects demand forecasts for further processing; a Supply and Demand Matching process component that combines the tasks necessary to ensure that sufficient material receipt elements exist to cover material demand; an External Procurement Trigger and Response process component that combines the tasks necessary for processing planned external procurement orders and provides an interface to purchasing from a supply planning perspective; a Logistics Execution Control process component that controls and monitors the supply chain execution activities necessary for the fulfillment of an order; and a plurality of service interface operations, each service interface operation being implemented for a respective process component, the operations comprising inbound and outbound operations, the outbound operation for a first process component being operable to send a message to a second process component of the plurality of process components, the second process component having an inbound operation for receiving the message, the passing of messages between an inbound and an outbound operation defining a message-based pair-wise interaction between the respective process components of the respective operations, the pair-wise interactions between pairs of the process components including interactions between: the Logistics Execution Control process component and the Inbound Delivery Processing process component; the Purchase Order Processing process component and the Supplier Invoice Processing process component; the Purchase Order Processing process component and the Sales Order Processing at Supplier process component; the Customer Invoice Processing process component and the Supplier Invoice Processing component; the Inbound Delivery Processing process component and the Supplier Invoice Processing process component; the Purchase Order Processing process component and the External Procurement Trigger and Response process component; the Logistics Execution Control process component and the Site Logistics Processing process component; and the External Procurement Trigger and Response process component and the Purchase Request Processing process component.