Dear Vijay T,
You have not mentioned the nature of your production, the number of machines, the number of operators work in the night time, noise by the machines etc. Have you conducted any study of the absence of the workers? How does it impact production? Are the deliveries delayed due to the absence?
One quick solution is to pay the night-shift allowance. However, once started, withdrawing it will be difficult.
The second solution is to rearrange the production schedule in such a fashion so as to make the night shift a little less strenuous.
The third solution is on the numbers of hours of work in the night shift. When your night shift starts and when it ends? For how many hours workers work in the night shift? If the numbers of hours are on par with the day shift then explore the possibility of reducing the number of hours.
The fourth solution is to identify the scope of automation. Will automation reduce the dependence on the workers in the night shift? If the machines are noisy then can the noise be reduced?
The last solution is to understand what happens during the night shift. Have you spent a night on the shop-floor? If not you then let someone else take stock of the situation during the night. As of now, you could be depending on the feedback from the Production or Operations Managers/Supervisors. However, when some third-party monitors the situation, suggestions for improvement may come up.
Thanks,
Dinesh Divekar