A machine shop can be a capital intensive business, because the purchase of equipment can require large investments. A machine shop can also be labour-intensive, especially if it is specialized in repairing machinery on a job production basis, but production machining (both batch production and mass production) is much more automated than it was before the development of CNC, programmable logic control (PLC), microcomputers, and robotics. It no longer requires masses of workers, although the jobs that remain tend to require high talent and skill. Training and experience in a machine shop can both be scarce and valuable.