500 word human resources paper

I need a 500 word answer to the following:

Short Case 1 (50 points). Company XYZ is a mid-sized R&D organization that is largely based on team work. As a result, semi-annual performance evaluations are conducted at the team and not individual level. Team A received a mediocre rating on the most recent performance evaluation. The manager explained that his appraisal was objective and was solely based on the mediocre quality of the last two projects the team completed which was also evidenced by mediocre customers’ evaluations.  Although the team accepted the rating as very objective, one team member expressed his strong disagreement. He said that his own contribution was error-free and he should not be punished for the mistakes of his team members. He demanded to change his performance rating from the mediocre to high.

1. As a manager, what would you do in this situation? What would be your response to the employee? Justify your answer. [This is a reactive approach. You need to deal with the situation as it is.]

               2. Proactively, would you do to avoid such situations in the future? Explain.