Take a step back and answer why do you need a bonus system ? Dan Ariely and other Psychology and Behavioral Economists claim that the value of bonuses is not big or even negative [0]. My experience is that bonuses tied to performance leads to a bad work environment, and if at all benefits only part of the people- the backstabbers or the geniuses [0] https://www.wired.co.uk/article/dan-ariely-bonuses-boost-act...
There’s a video that I really like, talking about the same research that knowledge based jobs, bonuses decrease performance. https://m.youtube.com/watch?v=u6XAPnuFjJc&feature=player_emb...
https://www.amazon.com/Punished-Rewards-Trouble-Incentive-Pr...