Appraising the What and the How
In my organisation a semestral (semi-annual) appraisal of performance is held to all employees. We evaluate WHAT they did and did not accomplish.
To do so, we use the semester plan and all indicators are hard. So, no bias there.
But equally important in our company culture is HOW you got to the indicator. This soft part is evaluated annually by means of a 360 evaluation made by an external consultant.
Anything found below expectation enters the employee development plan for the next semester. Its goals and indicators are negotiated, but the bar always raises on company demand. If a employee fails to obtain her/his goals for two successive assessments, he most probably will be dismissed.