1. A management device for an image forming apparatus, comprising: a status data collection unit that receives multiple types of status data from the image forming apparatus and stores received status data in a status database; a target data creation unit that creates multiple types of target data based upon said multiple types of status data; a first stage determination unit that determines said multiple types of target data as being above or below reference values set for each type; and a second stage determination unit wherein a weight value set for each status data type is attached to the determination results of said multiple types of status data of said first stage determination unit and as a whole of said multiple types of status data determines with majority logic for abnormal occurrence prediction.