A method of operating a building elevator system within a building having a plurality of landings (125a-125z), the method comprising: controlling a first elevator group comprising one or more elevator systems (101a-101e), wherein each of the one or more elevator systems (101a-101e) of the first elevator group comprises an elevator car (103a-103e) configured to serve a first range of landings ; controlling a second elevator group comprising one or more elevator systems (101f-101j), wherein each of the one or more elevator systems (101f-101j) of the second elevator group comprise an elevator car (103f-103j) configured to serve a second range of landings ; and characterized by : detecting at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to the amount of traffic within the second range of landings ; and adjusting a range of landings served by one or more elevator systems (101f-101j) of the second elevator group in response to at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to an amount of traffic within the second range of landings . controlling a first elevator group comprising one or more elevator systems (101a-101e), wherein each of the one or more elevator systems (101a-101e) of the first elevator group comprises an elevator car (103a-103e) configured to serve a first range of landings ; controlling a second elevator group comprising one or more elevator systems (101f-101j), wherein each of the one or more elevator systems (101f-101j) of the second elevator group comprise an elevator car (103f-103j) configured to serve a second range of landings ; and characterized by : detecting at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to the amount of traffic within the second range of landings ; and adjusting a range of landings served by one or more elevator systems (101f-101j) of the second elevator group in response to at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to an amount of traffic within the second range of landings . detecting at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to the amount of traffic within the second range of landings ; and adjusting a range of landings served by one or more elevator systems (101f-101j) of the second elevator group in response to at least one of the amount of traffic received by the first elevator group relative to the amount of traffic received by the second elevator group , and the amount of traffic within the first range of landings relative to an amount of traffic within the second range of landings . <EOS>