Method for operating a plant system for coating objects, in particular vehicle bodies, wherein a) a coating plant for coating objects is present at an operating site; b) in the coating plant a coating material is applied to the objects in at least one coating booth, through which an air flow is directed, which absorbs and removes arising overspray of the coating material; whereby c) the air flow is fed to a separating device of the coating plant, which is operated with a plurality of filter modules in which a majority of at least the solid materials is separated from the overspray; d) each filter module is replaced with an empty filter module after reaching a limit loading of overspray; e) a filter module is at least thermally partially regenerable; characterised in that f) the number of filter modules available at the operating site for the operation of the separating device defines an actual number; and g) the number of filter modules required at the operating site for the operation of the separating device defines a target number; and h) the difference between the actual number and the target number defines a demand number in case that the actual number is less than the target number, or defines a surplus number in case that the actual number is greater than the target number; and i) a filter module pool is provided comprising an inventory number of filter modules, at least a part of which is stored at a pool location that is different from the operating site of the coating plant; and j) a number of filter modules corresponding to the demand number is physically transferred from the filter module pool to the operating site, whereby the actual number is increased by the demand number and the inventory number is reduced by the demand number; or k) a number of filter modules corresponding to the surplus number is allocated to the filter module pool, whereby the actual number is reduced by the surplus number and the inventory number is increased by the surplus number. a) a coating plant for coating objects is present at an operating site; b) in the coating plant a coating material is applied to the objects in at least one coating booth, through which an air flow is directed, which absorbs and removes arising overspray of the coating material; whereby c) the air flow is fed to a separating device of the coating plant, which is operated with a plurality of filter modules in which a majority of at least the solid materials is separated from the overspray; d) each filter module is replaced with an empty filter module after reaching a limit loading of overspray; e) a filter module is at least thermally partially regenerable; characterised in that f) the number of filter modules available at the operating site for the operation of the separating device defines an actual number; and g) the number of filter modules required at the operating site for the operation of the separating device defines a target number; and h) the difference between the actual number and the target number defines a demand number in case that the actual number is less than the target number, or defines a surplus number in case that the actual number is greater than the target number; and i) a filter module pool is provided comprising an inventory number of filter modules, at least a part of which is stored at a pool location that is different from the operating site of the coating plant; and j) a number of filter modules corresponding to the demand number is physically transferred from the filter module pool to the operating site, whereby the actual number is increased by the demand number and the inventory number is reduced by the demand number; or k) a number of filter modules corresponding to the surplus number is allocated to the filter module pool, whereby the actual number is reduced by the surplus number and the inventory number is increased by the surplus number.