Title: Task allocation decisions at human–robot two-sided disassembly line 4.0 and SERU disassembly units Journal: International Journal on Interactive Design and Manufacturing (IJIDeM) Author: Najat Almasarwah Abstract: Human–robot cooperation plays a vital role in enhancing the advantages of employing humans and robots in disassembly processes, which leads to create several operating scenarios. Despite the importance of human–robot cooperation in the disassembly process, the existing literature has some limitations and does not appropriately cover resource skill level issues. The paper aims to design a human–robot two-sided disassembly (HRTSD) line and SERU disassembly units considering the variety in the disassembly times caused by the resources’ skill levels and the quality of End-of-Life products (EOLPs). The main contribution of this paper is to help the decision-makers choose between the HRTSD lines and SERU disassembly units in case EOLPs are assigned to be disassembled in the remanufacturing system. In this paper, two EOLPs are disassembled in a mixed model. The performance measures utilized for the behavior of the HRTSD lines and SERU disassembly units are the cycle time, output rate, and average skill variability. The average variability in skill is calculated based on the skill variability per resource(s) and task(s). Findings show that the HRTSD line can dominate the performance of SERU disassembly units as the average skill variability increases (≥0.20) resulting from the quality of EOLPs and resources’ skill levels, and vice versa.