In modern society, where the concept of a job for life is fading, deciding to seek new employment has become a natural phenomenon. However, the reasons for this decision can vary by generation, and frequent job turnover in the labor market is a social concern. Given the direct relationship between education and training and employee turnover, the Korea Research Institute for Vocational Education and Training (KRIVET) conducted a survey of individuals who have completed a work-study training program. This survey looked into the characteristics of the training, their job turnover status, and the reasons for their decision to seek new employment. The findings showed that the turnover rate was highest among Generation Z and was less than 20% for the Millennial, Generation X and older generations. The primary motivation cited for leaving a current position across generations was the pursuit of better employment conditions. The study also assessed perceptions of On-the-Job Training (OJT) and Off-the-Job Training (Off-JT), finding high levels of satisfaction with the competence of trainers and workplace instructors across both formats. In examining the relationship between training characteristics and job turnover, the study revealed that the factors influencing the decision to seek new employment varied by generation. For Generation Z, unlike other age groups, educational background and years of experience were significant factors in deciding to change jobs. The findings also confirm that for all generations, the content of OJT or the competency of the workplace instructors are a crucial determinant in the decision to change jobs, suggesting that companies should focus on aligning OJT closely with job requirements, beginning with the development and design phases of training programs.