Opposing Opinions on a Process

I am a manager for an IT group and my co-managers keep insisting on me changing my process and do what they want me to do. How do I handle these confrontations without being ugly or “giving” in and letting them feel like they win all the time? I just feel ganged up on and don’t see a problem with my process. The other teams I work with are pleased with the design and do not want it to change.