Computer Software Validation

Hi:

I’m from México, I have a question, we need to do a software validation in a pharmaceutical facilitie, but they don’t have all de GAMP IV SDS and SMDS documentation complete, like pseudocodes, they don’t have documented the error handling and data checking, also they don´t have if a parameter is a pass by value or by reference, is that documetation strongly necesary to comply with CSV?