investigation the validity of performance appraisal system of iranian custom

employee performance appraisal is one of the most powerful tools for measuring various figures in human resource management. this will eventually help employees to recognize their, and their weaknesses. this research investigates the validity of performance appraisal system for the iranian customs department using the singer model. the research method is descriptive and is based on survey study. the population of this research consists of 470 custom experts. having used simple random sampling; 140 were used as a sample size. the results indicated that performance appraisal system of iranian custom is not valid. this means that appraisal system is not effective in attaining goals and performing tasks. it is suggested to managers to consider training needs, salary and reward, communication and feedback in designing the performance appraisal system. it is only through this way that predetermined goals could be achieved.