When I was an electrical engineer building emergency wireless communications networks, I learned about the importance of having backups—sometimes the hard way, with a 3 a.m. phone call reporting a system is down and the backup system didn’t kick in.
I also learned never to rely on a sole-source supplier, because if for some reason that company couldn't deliver, you can’t build a product or make something work if it’s broken and you don’t have the parts to fix it. Have you ever had an ingredient supplier like that? Then you know what I’m talking about.