We've made a job descriptions manual, which contains an organizational chart and various job descriptions, and a training matrix. The training matrix lists all the procedures and work instructions each job description needs to be trained to. the job descriptions list responsibilities, who they report to, minimum education and skills required, and things of that nature.
we have a training manual that has all the courses (which are basically copies of the procedures and work instructions they need to be trained/indoctrinated in) that has a sign in sheet after each course. Within 3 months of hire, or implementation, each employee reviews the course/procedure and signs.
Then we have a form of competence assessment, where employee is evaluated for competence of each job description he is assigned. In addition, we have a performance management evaluation, which is a much more thorough evaluation of how the employee carries out every aspect of his job, what problems were noticed/corrected, where he is at, where we envision him progressing, and what he needs to do to get from point a to point b.
All of this will provide the evidence of what you are being asked. Changes implemented would be "employee scored low on competence assessment and was required to undergo more training, or reassigned a different job title". Also would be covered by any corrective or preventative actions generated from employee incompetence that resulted in more training. I'm not sure how to attach these documents, but send me an email (through private message) and give me your email and I'lll send all the documents pertaining to training