How can I renew a course for employees who need to take it year after year?

Summary:

We have a requirement for a group of employees (some new hires, others who taken the training before) to take the exact same training year after year, depending on when they're hired. The goal is to be able to tell the employee (these are temporary employees who work for two to four weeks) to go to the same course and repeat the course when they're hired the next year. Due to the way this group of employees is hired, the ability to assign the training is hampered by the number of employees and the fact that they could be hired