A purchasing entity directs the sourcing of one or more parts in a microprocessor-based method. The microprocessor-based method comprises obtaining over a computer network sourcing information from a primary supplier which identifies one or more third party secondary suppliers for one or more parts in a group of parts, ordering the group of parts from the primary supplier, and then issuing a release to the secondary supplier to ship the part to a predetermined location. A computer system for purchasing parts from a secondary supplier that executes the method is also provided.