A process control system (1; 2; 3) performing control of an industrial process implemented in a plant, the process control system (1; 2; 3) comprising: a network (N; N1, N2) provided in the plant; a plurality of field devices (10; 40) connected to the network (N; N1, N2), each of the plurality of field devices (10; 40) being configured to perform at least one of measurement and actuation required for control of the industrial process; and at least two controllers (20; 20a, 20b; 60a, 60b, 60c) connected to the network (N; N1, N2), the at least two controllers being configured to communicate with each other and perform redundant operations which are synchronized with each other, each of the at least two controllers (20; 20a, 20b; 60a, 60b, 60c) including: a computer hardware comprising a processor and a memory; a hypervisor on the computer hardware, the hypervisor being configured to achieve mutually synchronous operation between the at least two controllers which are synchronized with each other, and a control unit (23, 24) on the hypervisor, the control unit comprising an operating system that runs on the hypervisor and an application that runs on the operating system to control operations of the field devices via the network, wherein the hypervisor is configured to allow the computer hardware to be changed into a different hardware which is different from the computer hardware without changing the operating system and the application. a network (N; N1, N2) provided in the plant; a plurality of field devices (10; 40) connected to the network (N; N1, N2), each of the plurality of field devices (10; 40) being configured to perform at least one of measurement and actuation required for control of the industrial process; and at least two controllers (20; 20a, 20b; 60a, 60b, 60c) connected to the network (N; N1, N2), the at least two controllers being configured to communicate with each other and perform redundant operations which are synchronized with each other, each of the at least two controllers (20; 20a, 20b; 60a, 60b, 60c) including: a computer hardware comprising a processor and a memory; a hypervisor on the computer hardware, the hypervisor being configured to achieve mutually synchronous operation between the at least two controllers which are synchronized with each other, and a control unit (23, 24) on the hypervisor, the control unit comprising an operating system that runs on the hypervisor and an application that runs on the operating system to control operations of the field devices via the network, wherein the hypervisor is configured to allow the computer hardware to be changed into a different hardware which is different from the computer hardware without changing the operating system and the application. a computer hardware comprising a processor and a memory; a hypervisor on the computer hardware, the hypervisor being configured to achieve mutually synchronous operation between the at least two controllers which are synchronized with each other, and a control unit (23, 24) on the hypervisor, the control unit comprising an operating system that runs on the hypervisor and an application that runs on the operating system to control operations of the field devices via the network, wherein the hypervisor is configured to allow the computer hardware to be changed into a different hardware which is different from the computer hardware without changing the operating system and the application.