People that have mastered the art of hardware refresh - how do you do it?

It's 2010. You buy a firewall for you datacenter. You know it'll be EOL in 7 years time - so you budget for a replacement in the future.

2018 comes by. You use that budget and get a new firewall. Easy.

But how did you end up in this magical land of controlled hardware replacement?

How much red tape did you have to break?

Or is it still a struggle?