On-the-job training (OJT) requires the greatest amount of monitoring to control variation because it involves direct, hands-on experience in the work environment. OJT can vary significantly based on the trainer's expertise, the work conditions, and the trainee's learning pace. This variability necessitates close monitoring to ensure that the training is effective, consistent, and aligns with organizational standards and goals. Unlike more controlled environments like computer-based training or classroom lectures, OJT's dynamic nature can lead to a greater risk of variation in the training outcomes1.
References: 1: ASQ - Manager of Quality/Organizational Excellence Certification CMQ/OE.