This sub-class includes the specialised installation of industrial (i.e, used for production and/or processing operations) machinery. However, the installation of equipment that forms an integral part of buildings or similar structures, such as installation of escalators, electrical wiring, burglar alarm systems or air-conditioning systems, is classified as construction. Units in this sub-class are primarily engaged in: •installation of industrial machinery in industrial plant •installation of industrial process control equipment •installation of other industrial equipment (e.g., communications equipment, mainframe and/or similar computers, irradiation and/or electromedical equipment, etc.) •dismantling large-scale machinery and/or equipment •activities of millwrights •machine rigging •installation of bowling alley equipment •mechanical engineering works