time-and-motion study
noun [ C usually singular ] uk/ˌtaɪm.əndˈməʊ.ʃən ˌstʌd.i/ us/ˌtaɪm.ənˈmoʊ.ʃən ˌstʌd.i/
（尤指工商业领域的）时间与动作研究（旨在找到最有效率的工作方法）
a study of work methods, especially in industry or business, in order to find the most effective way of operating