eng Science and Education Publishing Journal of Business and Management Sciences 2333-4533 2022-07-21 10 3 147 156 10.12691/jbms-10-3-6 JBMS20221036 article Hui-Sung Kao 1 Ming-Jiun Tsai pearly.cpb@msa.hinet.net 1 Department of Accounting, Feng Chia University, Taichung, Taiwan This study discusses the effect of supplier-customer relationships in the supply chain on operational risk and takes into account earnings management to explain the increment and modulation effect on supply chain relationship and operational risk. With listed and over-the-counter (OTC) companies in Taiwan from 2009 to 2018 as subjects, this study finds in its empirical results that in supplier-customer relationships, suppliers may obtain related information in due time and adopt a better cooperation mode in the supply chain to reduce operational risk when they have a higher key customer concentration. However, in such a case, their operational risk may increase with a higher key customer concentration if enterprises take real earnings management to manipulate earnings. http://pubs.sciepub.com/jbms/10/3/6/jbms-10-3-6.pdf supply chain management key customer operational risk earnings management