The quality research purpose were 1) to investigate work roles and responsibilities, which are elements of the performance appraisal model of first line managements in Thai foundry industry, 2) to development the performance appraisal model of first line managements in Thai foundry industry, and 3) to development the performance appraisal manual of first line managements in Thai foundry industry. The participants were a first line management in the production line in a medium Thai foundry industry from 37 companies. The statistics used in the research included percentage, standard deviation, consistency index, and the content validity index. The research result revealed the following. 1) Work roles and responsibilities as the components of the performance appraisal model of first line managements in Thai foundry industry. It was found that had two key functions and nine units of competence. The nine elements of competence were divided into 3 levels (1) practitioner head level 13 jobs, (2) supervisor head level 21 jobs, and (3) professional skilled level 15 jobs. 2) The performance appraisal model of first line managements in Thai foundry industry obtained from the discussion hearing demonstrated six stages of the development and after the model was evaluated and developed by the experts, it was found that the model was in the highest level. 3) The performance appraisal manual of first line managements in Thai foundry industry form consisted of knowledge assessment, skill assessment, and behavioral assessment. After the performance appraisal manual was evaluated (content validity index) by the experts, it was found that the manual was in 1.00 level. And the performance appraisal manual obtained was applied with six samples and some were under 80% of the performance benchmark and had to enroll into individual development plan for catching up with the organization standard on the knowledge and skills
