Yes, it is mandatory, as per our act in Maharshtra, for your company to maintain Form 23 and Form 24.
If you have any other methods of storing these details, as per your own companies policy & Procedures, like what you are now practicing or in companies that have computerised payroll system, one is required through a letter addressed to the "Commissioner of Labor of your region" inform him about this practice. Your letter must have all the formats of leave record and attendance record for his reference and approval. The Commissioner will put his seal of acceptance and you can continue with your practice without any fear.
Just for your information, may IT companies and companies those who have adopted to latest HRIS system of maintaining these data do not do this simple process and end up paying that Labor officer bribe to handle this for them.
All the best and hope this is helpful.
From Saudi Arabia, Riyadh