This is because such workers who attend to customer complaints, installation work, etc., would be entitled to certain allowances like outstation allowance to compensate for their additional hours of work. However, if you extend the working hours to consider overtime payments, there will be no limit to overtime wages. It is true that when a worker works in a factory for more than nine hours in any day or for more than forty-eight hours in any week, he shall, in respect of overtime work, be entitled to wages at the rate of twice his ordinary rate of wages. This is a mandatory provision as per section 59(1) of the Factories Act. But here the question is whether the expression "a worker works in a factory" means "a worker working in the factory in which he is employed" or "a worker works in any factory" or "a worker working anywhere he is directed to work."
In the Avery case, the court, while dismissing the petition by the aggrieved worker, has kept open the possibility that he can raise an industrial dispute to get paid for work outside the factory but cannot demand overtime wages for the work. See the attachment also.