An imaging device supervision system stores data indicating, for instance, the number of sheets of paper supplied from each paper supply cassette in a copying machine, and/or the number of times the toner has been replenished, and the amount of toner cartridges in stock are stored in a copying machine supervision data base which is constructed, stored and maintained in a storage device, such as a hard drive. The supervision system updates the stock amounts for each size of paper based on the data indicating the number of sheets of paper supplied, and formulates a consumable item delivery plan according to delivery conditions set in a delivery schedule setting screen 91, to reduce the downtime due to stocks of consumable items being exhausted in an imaging device. Further, the amount of toner cartridges in stock are updated by means of the number of times the toner has been replenished, and the stock data are displayed on a status information screen 66.