This paper recommends a new kind of assembly line rebalancing and worker assignment problem, taking ergonomic risks into account. Assembly line rebalancing problem (ALRBP) occurs when a current line must be rebalanced due to conditions such as changes in demand, production processes, product design, or quality issues. Although there are several research attempts on ALRBP in the relevant literature, only a few studies consider workers as unique individuals. This paper aims to solve the double reassignment problem: tasks to workers and workers to stations, considering ergonomic risk factors. This paper is the first study that comprises worker assignment and ergonomic constraints in ALRBP literature to the best of our knowledge. Objectives of our novel problem are to minimize rebalancing cost, which includes transportation of tasks and workers and minimize stations' ergonomic risk factors. A randomized constructive rule-based heuristic approach is developed to cope with the problem. The proposed solution approach is applied to benchmark data, and obtained results are promising. Moreover, the proposed solution approach is implemented in an automotive parts manufacturing plant.

Purpose Various approaches and algorithms have been proposed since the 1950s to solve the assembly line (AL) balancing problem. These methods have established an AL configuration from the beginning. However, a prebalanced AL may have to be rebalanced in real life for many reasons, such as changes in the cycle time, production demand, product features or task operation times. This problem has increasingly attracted the interest of scientists in recent years. This study aims to offer a detailed review of the assembly line rebalancing problems (ALRBPs) to provide a better insight into the theoretical and practical applications of ALRBPs. Design/methodology/approach A structured database search was conducted, and 41 ALRBP papers published between 2005 and 2022 were classified based on the problem structure, objective functions, problem constraints, reasons for rebalancing, solution approaches and type of data used for solution evaluation. Finally, future research directions were identified and recommended. Findings Single model, straight lines with deterministic task times were the most studied type of the ALRBPs. Eighteen percent of the studies solved worker assignment problems together with ALRBP. Product demand and cycle time changes were the leading causes of the rebalancing need. Furthermore, seven future research opportunities were suggested. Originality/value Although there are many review studies on AL balancing problems, to the best of the authors’ knowledge, there have been no attempts to review the studies on ALRBPs.