The term 'WHYS' is an acronym for 'What, How, Why, and Wherefores'. It is a tool used in problem solving to help identify the root cause of a problem. It is used to ask questions about the problem, such as what caused it, how it happened, why it happened, and what can be done to prevent it from happening again. The acronym is often used in business and engineering contexts to help identify and solve complex problems.