To be very frank, I would say that this is one of the Labour Acts which remains unenforced. Many establishments, even in the manufacturing sector and those with trade unions, are yet to get their own Standing Orders certified! Even PSUs are there without certified Standing Orders.
Therefore, practically, no establishment would go for certification due to two main reasons. Once you draft standing orders, the certifying officer would require a trade union representative to certify it first as accepted service conditions. In the absence of a trade union, he would select a few employees as signatories to standing orders. In many cases, these signatories will then acquire a feeling that they are leaders of the other employees since they are also signatories to the most important document defining the employee-employer relationship. This could be avoided if standing orders are kept in freezers until the labor-enforcing authorities require that standing orders should be made and certified.
Therefore, I also advise that as long as your number of workmen does not reach 100, you may follow the status quo. Alternatively, you can prepare an Employee Handbook including all the relevant matters for which provisions are required to be made in the standing orders and communicate with the employees. This can also be made part of the employee joining document, and you can take acknowledgment from the employees as having read, understood, and accepted the content as applicable to them. This would then become part of the employment contract.