Training is important if you want to have consistent results.  For training to be effective you most have a training manual with full descriptions for each task.  This is what the teacher should use for each instruction session.  The common practice of having a new hire work with a more seasoned staff member does not assure that the process will be executed the same way that you intended.  Furthermore, training needs to be tested and reinforced when necessary.  A significant part of every supervisor’s job is to observe how tasks are done and note how the individual performs in relation to the written method.  If what the employ is doing yield better results, change the written method and re-train the rest of the staff.  If the results are not better, re-train the employees.