A system for providing products to a customer operates with an open purchase order having an acceptable inventory range bounded by a lower and an upper limit for each product supplied to the customer. The system includes a storage unit, a first processing unit that maintains a product inventory count, and a second processing unit that monitors the product inventory count. A system for transferring electronic files includes a first processing unit that stores and transfers the electronic file, generates a pointer associated with the transferred electronic file, generates a reference electronic file and thereafter includes the pointer in the reference electronic file. A second processing unit then displays the reference electronic file. A system for generating composite electronic files includes a first processing unit having composite locations including component electronic files, and generating the composite electronic files when the respective composite location is accessed from a second processing unit.