Refresher training is an aspect of retraining taken by a person already qualified or previously assessed as competent in a field with the intention of updating skills and/or knowledge to a changed , or providing the opportunity to ensure that no important skills or knowledge have been lost due to lack of use. In industry it is also used to upgrade performance of personnel faced with workplace changes or who use obsolete, deprecated, or outdated work procedures, as a method for improving productivity, customer service, employee satisfaction and retention, and workplace health and safety.