Where an employee replaces another employee on the same job within a 24-hour period. This helps to maximise the output that can be produced from the current premises and existing machinery. Employees may be paid a premium rate for working ‘unsociable’ hours that may be, say, between 1.2 to 1.6 times their usual hourly rate. Therefore, if premium rates are applied shift work increases labour costs. Labour costs may also increase if extra supervision is required to operate the shift. However, it may help to reduce unit costs overall, as a result of greater capital utilisation, as well as ‘off-peak’ utility charges.