Mass customization could be considered as a new trend in the apparel industry. Not only, the fashion industry has limitations of the short life cycle and low predictability market but its supply chain also faces many obstacles to achieve this customization with a high level of customer satisfaction and more flexibility at low cost. The present study aims to address the factors affecting the performance of supply chain. That’s why a survey and individual interviews have held with apparel supply chain professionals in order to focus on these factors and construct the relationship among them through simulation and modeling using a system dynamic approach. The results have revealed that the product variety, lead time, return policy and quality levels affected dramatically the supply chain profit under mass customization. Moreover, some potential areas have been suggested for further studies in order to enhance the supply chain profitability whenever mass customization system is applied within the apparel industry.