University of Tehran Press Interdisciplinary Journal of Management Studies 2981-0795 8 2 2015 04 01 A Flexible Integrated Forward/ Reverse Logistics Model with Random Path-based Memetic Algorithm الگوریتم ممتیک بر پایة مسیرهای تصادفی در یک مدل انعطاف‌پذیر و یکپارچة رو به جلو/ بازگشتی 287 313 52635 10.22059/ijms.2015.52635 EN Ehsan Yadegari Faculty of Management and Accounting, Shahid Beheshti University, Tehran, Iran Hesamaddin Najmi Department of Industrial Engineering, University of Tehran, Iran Morteza Ghomi-Avili Faculty of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran Mostafa Zandieh Faculty of Management and Accounting, Shahid Beheshti University, Tehran, Iran Journal Article 2014 10 06 Due to business and environmental issues, the efficient design of an integrated forward/reverse logistics network has recently attracted more attention from researchers. The significance of transportation cost and customer satisfaction spurs an interest in developing a flexible network design model with different delivery paths. This paper proposes a flexible mixed-integer programming model to deal with such issues. The model integrates the network design decisions in both forward and backward logistics networks, and also applies three kinds of delivering modes (normal delivery, direct shipment, and direct delivery) which enrich the model to be able to deliver the products to customers by distribution-skipping the mid-process strategy in order to deliver products in more flexible paths to customer zones. To tackle with such an NP-hard problem, a memetic algorithm (MA) with random path-based direct representation and combinatorial local search methods is developed. Numerical experiments are conducted to demonstrate the significance and applicability of the model as well as the efficiency and accuracy of the proposed solution approach. https://ijms.ut.ac.ir/article_52635_f6c1a09916f569b28602d1290f380cfb.pdf