Oracle iProcurement empowers any employee to enter and submit a requisition online, eliminate the need for the buyer to re-key data, enforce Company’s requisition approval authority hierarchy, enforce Purchasing Policy, automatically source requisitions from outstanding blanket purchase agreements or quotations received from suppliers, deliver electronic notifications where action or advice to an interested party is required (i.e. Approval or Confirmation of approval / rejection).
This nice document by Ranu Srivastav explains all the basic steps.