For a particular make of DCS selection, SO many parameters to be considered apart from Technical like logistics support, mandatory spares etc.
For Control system selection like DCS or PLC operation philosophy, no. of IOs and critical loops etc
We can guide you on how to find out the right solution for your application domain / technology segment. But we require more inputs on your requirements. Basically if you agree with me, the requirements itself forms a basis of selection of specifications for your solutions. I think I have already given you an approach to get results, but still if you need further help, pls feel free to revert with your complete requirements and application domain directly on our email id : [email protected]
The study does take some more time. I will finish it at may 2008. But after 1 september I will have some first results. You could also attend the online survey to get the report for free.