If you understand a system’s capability, what is the point of having a target? A target cannot improve capability, only improving the system will lead to improved capability.
If you don’t understand a system’s capability, a target is no more than a guess. The guess will either be beyond or within the system’s capability – either way it is of no value.
Using targets can limit performance (if the target is below current capability). More usually, targets cause unnecessary stress (when they are beyond current capability) and people learn to cheat (rather than learning to learn).
Instead of using arbitrary measures to drive people to cheat, it is much more sensible to learn from variation.
Managers believe they should manage the activity of the worker, they couldn’t be more wrong.