There is no reliable method for evaluating developer performance, and involving a committee doesn't change that. Bearing that in mind it is important to cynical

There is no reliable method for evaluating developer performance, and involving a committee doesn't change that. Bearing that in mind it is important to cynically evaluate what these tools are for - a form of soft power for managers, so they have carrots and sticks to use when enforcing some sort of team discipline. There probably is some sort of objective "performance" that we can't measure directly. Some programmers are beasts and obvious pillars of a company. Others are disasters that need to be sacked. Most are in a grey area where they aren't obviously on an extreme. Any system can pick up this distinction and make the necessary decisions. But all the theatre isn't a tool for performance, it is a tool for discipline. No system can rank people over an unmeasureable metric.