If the goal is to increase the productivity of the employees, then what you want is for the employees to be trying harder. To do that you'll want to incentive t

If the goal is to increase the productivity of the employees, then what you want is for the employees to be trying harder. To do that you'll want to incentive trying hard, e.g. through bonuses. The main reason bonuses are awarded for achieving good outcomes instead of for trying hard is because the former is easier to measure. Intentionally rewarding the achievement of good outcomes (which is a matter of chance) instead of good efforts will lead to strife, as those who put in just as much work but weren't as lucky will feel cheated.