Has anyone successfully brought formal methods to an area of code that is newly being developed?

I have successfully convinced management to allow me to use formal methods on portions of very old code (~17 years old at the time) that are being rewritten.. but I've never been able to get management on board with the time required for new development with formal methods. The planning time up-front is more than what a lot of companies are willing to tradeoff for time-to-market.