Performance appraisal is a review of an employee's job performance to identify strengths and weaknesses. It should be conducted periodically to provide feedback to employees and determine training, compensation, and promotion decisions. The success of performance appraisals depends on supervisors completing objective reviews and employees being willing to improve. While traditional methods like checklists and rankings are common, modern approaches like 360-degree feedback and management by objectives are increasingly used. An effective process involves setting standards, measuring performance against them, discussing results, and taking corrective actions. However, performance appraisals also have limitations like bias that must be addressed.