The thing is, performance management and performance review are ways to formalize promotion and firing decisions and protect the company from being dragged to court on those grounds.
The truth is, every good enough manager of a 5-10-person team knows exactly who the best and the worst single performers are. Taking them out of the picture and repeating the process, they likely sort their reports on a performance scale with quite precision.
(if you cannot do that, chances are that you are not a good enough manager)
The devil is in the detail: explaining that sorting algorithm to the reports. Most of the time, it is impossible. Moreover, it is sometimes hard to argue with the worst underperformer if they are actively pushing back. That's why corporations need a formal process.
The truth is, every good enough manager of a 5-10-person team knows exactly who the best and the worst single performers are. Taking them out of the picture and repeating the process, they likely sort their reports on a performance scale with quite precision.
(if you cannot do that, chances are that you are not a good enough manager)
The devil is in the detail: explaining that sorting algorithm to the reports. Most of the time, it is impossible. Moreover, it is sometimes hard to argue with the worst underperformer if they are actively pushing back. That's why corporations need a formal process.