System Development?

Currently we are trying to automate a business process in a lean but mean company. However the issue on this matter is they dont have a standardized data. They want a system that can be customizable whenever they want to change it, which i dont agree….i told them to “watch out” if they want a system with NO standard datas. it just provides gaps for errors. What’s your opinion on standardization? If you where in my place.. what would you propose to convince them that this is an urgent and important matter ?