A management device for managing a component mounter that mounts components onto a substrate using some of constituent elements each selected from one of constituent element groups each including the constituent elements. One group is a nozzle group including nozzles. The device includes: a true displacement amount calculator that calculates, for each target component which is the component, a true amount of displacement which is a sum of (i) an amount of pickup displacement being an amount of displacement between the target component and a target nozzle being one of the nozzles and picks up the target component and (ii) an amount of correction being an amount of offset of a position of the target nozzle when picking up the target component; and a statistical processor that performs parameter estimation for a predetermined statistical model using the true amount to calculate a degree of malfunction of each constituent element.