Performance bonuses are an interesting but flawed idea. The notion that someone should be paid according to the quality, or quantity, of their work, or even a combination of the two, at first sounds like an excellent idea. But it's not. Greed quickly finds a way to circumvent commonsense. Some of the most common abuses involve bonus based on financial performance. Simply cook the books to maximise the bonus. The criteria for performance bonuses soon become be all and end all of production and quickly defy common sense unless very carefully thought out. Paid a bonus based on the weight of screws your factory produces in a month? Make giant size screws which are easy to manufacture but no one has much use for.