Dear PROFESSIONAL.
When it is model standing orders as per the Industrial Employment Standing Orders Act, under BIR Act,1946 there is no need to separately getting certified as the act becomes applicable, if during prceeding 12 months the strenth of workers are morethan 100.
It doesnot matter whether the workers union signs it or not. The standing orders automatically becomes applicable
In this matter you take into confidence the Labour Officer concerned. H e will do the needful.