A combination of a mobile harvester, a first receiving vehicle and a second receiving vehicle, wherein the mobile harvester comprises: a material conveyance subsystem configured to convey material from the harvester to a first receiving vehicle through a spout; a fill sensor configured to generate a fill level sensor signal indicative of a fill level of material in the first receiving vehicle; a fill level detector configured to identify an overall fill level in the first receiving vehicle based on the fill level sensor signal and to generate an overall fill level sensor signal indicative of the overall fill level; characterised in that it further comprises a fill parameter generator configured to generate a fill parameter indicative of when or where the first receiving vehicle will reach a given fill level based on the overall fill level sensor signal; and a communication system configured to communicate the fill parameter to a mobile application running on a mobile device in the second receiving vehicle; and wherein the mobile application on the mobile device in the second receiving vehicle comprises a fill parameter output system configured to generate an output of an indication of the fill parameter to an operator of the second receiving vehicle through a user interface mechanism. wherein the mobile harvester comprises: a material conveyance subsystem configured to convey material from the harvester to a first receiving vehicle through a spout; a fill sensor configured to generate a fill level sensor signal indicative of a fill level of material in the first receiving vehicle; a fill level detector configured to identify an overall fill level in the first receiving vehicle based on the fill level sensor signal and to generate an overall fill level sensor signal indicative of the overall fill level; characterised in that it further comprises a fill parameter generator configured to generate a fill parameter indicative of when or where the first receiving vehicle will reach a given fill level based on the overall fill level sensor signal; and a communication system configured to communicate the fill parameter to a mobile application running on a mobile device in the second receiving vehicle; a material conveyance subsystem configured to convey material from the harvester to a first receiving vehicle through a spout; a fill sensor configured to generate a fill level sensor signal indicative of a fill level of material in the first receiving vehicle; a fill level detector configured to identify an overall fill level in the first receiving vehicle based on the fill level sensor signal and to generate an overall fill level sensor signal indicative of the overall fill level; characterised in that it further comprises a fill parameter generator configured to generate a fill parameter indicative of when or where the first receiving vehicle will reach a given fill level based on the overall fill level sensor signal; and a communication system configured to communicate the fill parameter to a mobile application running on a mobile device in the second receiving vehicle; and wherein the mobile application on the mobile device in the second receiving vehicle comprises a fill parameter output system configured to generate an output of an indication of the fill parameter to an operator of the second receiving vehicle through a user interface mechanism.