Provided is a resistive random access memory device that includes a storage node connected to a switching device. When the external device is not fitted with, the processing is interrupted, and when a fitting of the external device is recognized, the interrupted processing is restarted. Communication relationships can be established between the activity diagrams by using appropriate means. And, the controller is configured to dynamically calculate the success rate of each recovery procedure, modify the recovery sequence based on the success of the seek recovery operation and based on the success rate of recovery procedures providing the success.