A purchase requisition (PR) is an internal document used by a STORE Manager to maintain minimum stock levels for all departments. To create a PR in SAP, the material, quantity, price, plant, storage location, delivery date, and transaction codes ME51N, ME52N, or ME53N are required. ME51N is used to create, ME52N to change, and ME53N to display a PR while ME5A provides a list of existing PRs.