Abstract: The invention pertains to a maskless lithography system for transferring a pattern onto a surface of a target, comprising at least one beamlet optical unit for generating a plurality of beamlets, at least one measuring unit for measuring properties of each beamlet, at least one control unit for generating and delivering pattern data to said beamlet optical unit, said control unit being operationally coupled to said measuring unit for identifying invalid beamlets which have a measured property value outside a predefined range of values for said property at least one actuator for inducing a shift of said beamlet optical unit and said target with respect to one another, wherein said actuator is operationally coupled with said control unit, said control unit determining said shift, positioning valid beamlets at the position of said invalid beamlets, thus replacing said invalid beamlets with valid beamlets.