That's what they say the goal is. But I suspect their main concern is to make sure it's not gruesome for those in attendance including the media. Guillotine would be the quickest way of conducting the execution but it would also quickly end executions.
It also needs to be a method that isn’t pharmacologically complicated, because manufacturers and pharmacists refuse to be complicit in this today. That’s the main reason, and also a reason Alabama has botched so many executions in recent years with experimental drugs and untrained executioners.
