Abstract: Ordering, customizing, and managing a hierarchy of keys and locks. In an embodiment, a keying tree is graphically generated to comprise a key representation and at least one lock representation. The key representation represents at least one master key, as a root node, and comprises a key-name input, a key-quantity input, and a key-deletion input. The at least one lock representation represents at least one locking device, as at least one leaf node, and comprises a lock-name input, a lock-build input, a lock-quantity input, and a lock-deletion input.