Line-hybrid seru system conversion: Models, complexities, properties, solutions and insights

•Formulate several main models of line-hybrid seru system conversion in an integrated framework.•Clarify the complexity of line-hybrid seru system conversion in detail.•Develop exact and heuristics algorithms to solve the different scale instances.•Propose managerial insights and find an interesting phenomenon.

As an innovation of production mode, seru production was successfully implemented in Asian electronic industry such as Canon and Sony. Motivated by the benefits from seru production, our study focuses on investigating the fundamental principles of converting an assembly line to a hybrid system with serus and a short line (line-hybrid seru system conversion). We formulate several main models of line-hybrid seru system conversion in an integrated framework by combining the two evaluated performances (i.e., makespan and total labor hours) with the four constraints (i.e., worker allocation, seru formation, seru load and short-line scheduling). Subsequently, we clarify the complexity of line-hybrid seru system conversion in detail. Moreover, we analyze the properties of line-hybrid seru system conversion by dividing the whole solution space into several sub-spaces. Also, we propose exact and heuristics algorithms to solve the different scale instances. Finally, we provide some insights on how to construct a hybrid seru system and how to schedule on the hybrid seru system by investigating the extensive experiments. We find an interesting insight that the worker with the average skill, not the worker with the best/worst skill, should be left in the short line.