A support device for generating an executable program executed on a first programmable logic controller (PLC 1) including a processor, a memory (104, 106), and a network interface, the support device comprising: a first input unit configured to receive information defining, on a data-by-data basis, variables for data handled by the first programmable logic controller (PLC 1); a second input unit configured to receive a source program expressing processing executed on the first programmable logic controller using the defined variables; characterized in that the support device further comprises: a third input unit configured to, when a first variable indicating first data handled by the first programmable logic controller (PLC 1) is placed in correspondence, via a network, with a second variable indicating second data handled by a second programmable logic controller (PLC 2) connected to the first programmable logic controller (PLC 1) via the network, receive information that identifies a type of the second programmable logic controller (PLC 2) in association with the first variable; and a generation unit configured to generate the executable program using the information defining the variables and the source program, wherein the generation unit adapts a data structure of the first data secured in the memory (104, 106) in correspondence with the first variable in accordance with the type of the second programmable logic controller (PLC 2). a first input unit configured to receive information defining, on a data-by-data basis, variables for data handled by the first programmable logic controller (PLC 1); a second input unit configured to receive a source program expressing processing executed on the first programmable logic controller using the defined variables; characterized in that the support device further comprises: a third input unit configured to, when a first variable indicating first data handled by the first programmable logic controller (PLC 1) is placed in correspondence, via a network, with a second variable indicating second data handled by a second programmable logic controller (PLC 2) connected to the first programmable logic controller (PLC 1) via the network, receive information that identifies a type of the second programmable logic controller (PLC 2) in association with the first variable; and a generation unit configured to generate the executable program using the information defining the variables and the source program, wherein the generation unit adapts a data structure of the first data secured in the memory (104, 106) in correspondence with the first variable in accordance with the type of the second programmable logic controller (PLC 2). a third input unit configured to, when a first variable indicating first data handled by the first programmable logic controller (PLC 1) is placed in correspondence, via a network, with a second variable indicating second data handled by a second programmable logic controller (PLC 2) connected to the first programmable logic controller (PLC 1) via the network, receive information that identifies a type of the second programmable logic controller (PLC 2) in association with the first variable; and a generation unit configured to generate the executable program using the information defining the variables and the source program, wherein the generation unit adapts a data structure of the first data secured in the memory (104, 106) in correspondence with the first variable in accordance with the type of the second programmable logic controller (PLC 2).