This document outlines different aspects of performance appraisal systems including definitions, importance, processes, methods, barriers, and limitations. It discusses the purposes of performance appraisal including development, feedback, administrative decisions, organizational maintenance, and legal requirements. Common methods described are ranking, paired comparison, forced distribution, graphic rating scales, MBO, BARS, assessment centers, and 360-degree/720-degree feedback. Barriers mentioned are personal bias, halo/horn effects, lack of standards, stress on individuals over performance, and lack of communication.