Are Behaviorally Anchored Rating Scales Superior To More General Approaches?
As with most things related to performance management the success of a BARS (behaviorally anchored rating system) approach to employee reviews depends on how well the system is implemented. In theory, a BARS system, if properly implemented should result in fairer, and more accurate assessments of employee performance. In theory, they are indeed better than more vague rating systems where it's hard to get any two people to agree on what a particular rating item means.
However, BARS still involves RATINGS, and ratings still have inherent flaws, the most notable being that ratings themselves (let's say assigning some number to "reflect" performance) are not very helpful in helping employees improve performance because too much information is lost. Another problem is that there is a tendency for people to believe that BARS system ratings are objective, and that is definitely not the case. Ratings cannot, by definition, be objective, because they involved labelling and generalizations.
The issue with BARS is that it requires extensive upfront analysis necessary to identify the job behaviors. Without that, it's no improvement. And, if you are going to invest all that time into the upfront analysis, maybe it makes more sense to use that data without a rating system per se, or use it in a way similar to how goals and objectives are used in a Management by Objectives system (MBO).