When a company offers additional compensation based on the contingency of certain goals being met by individual employees, this is referred to as?

When this refers to individual employees I would say it is a bonus system whereby if say a driller drills greater than a certain length per shift then he gets a bonus for the extra length drilled. The trouble with this system, especially in an underground mine is that it can foster dangerous practices and shortcuts and rushing by the miners to achieve the extra bonus, especially if the regular pay is not that much so the miners can be hurt or the quality of the work can suffer also.