en Supply Chain Management and Logistics Supply Chain Management and Logistics پژوهشی Original <span style="font-size:11pt"><span style="line-height:normal"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><i><span style="font-size:10.0pt"><span style="letter-spacing:-.25pt">As one of the main challenges of the 21st century supply chain, complexity has become a crisis, costly, and difficult for many supply chain managers. </span></span></i><i><span lang="EN-GB" style="font-size:10.0pt"><span style="letter-spacing:-.25pt">However, few studies have prioritized this strategy</span></span></i><i><span style="font-size:10.0pt"><span style="letter-spacing:-.25pt">. This study aimed to investigate the effect of supply chain complexity on competitiveness performance in the Iran Khodro Company. To achieve this goal, the relationship between different sources of complexity (upstream complexity, domestic production, and downstream complexity) and competitiveness performance is examined using a conceptual model. </span></span></i><i><span lang="EN-GB" style="font-size:10.0pt"><span style="letter-spacing:-.25pt">The statistical population of this study included all Iran Khodro experts, whose number reached 218 in 2022. Owing to the limitations of the statistical community, all members were selected as a sample.</span></span></i><i> </i><i><span lang="EN-GB" style="font-size:10.0pt"><span style="letter-spacing:-.25pt">The collection tools for this study included two standard questionnaires: the supply chain and Porter&#39;s competitiveness performance.</span></span></i><i><span style="font-size:10.0pt"><span style="letter-spacing:-.25pt"> The content validity of the questionnaires was confirmed by experts, its construct validity was confirmed by confirmatory factor analysis, and the reliability of the questionnaires was confirmed using Cronbach&#39;s alpha coefficient and the combined reliability index. The collected data were analyzed using the structural equations in the LISREL software. The results of hypothesis testing show that, in general, supply chain complexity has a significant inverse effect on competitiveness performance.</span></span></i></span></span></span></span><br> &nbsp; Complexity Competitiveness, Iran Khodro, Supply chain 133 148 http://iors.ir/journal/browse.php?a_code=A-10-5331-2&slc_lang=en&sid=1 Asadollah Alirezaei alirezae.emba@gmail.com 00031947532846002774 00031947532846002774 No Young Researchers and Elite Club, sirjan Branch, Islamic Azad University, sirjan Hoda Moradi h.moradi@iauyazd.ac.ir 00031947532846002775 00031947532846002775 Yes Department of Management, Yazd Branch, Islamic Azad University, Yazd