Seru system balancing: Definition, formulation, and exact solution

Seru production can reduce makespan, labor hours and manpower by improving workers' workload balance based on the reconfiguration of workers. Therefore, this study focuses on the fundamental principles of seru system balancing. For a seru, we define and formulate seru balance (SB) to describe workloads balance of the workers in the seru. For a seru system containing more serus, the seru system balance (SSB) needs to be evaluated from workloads balance of all workers and workloads balance among all serus. Consequently, we define and formulate intra-seru system balancing (Intra-SSB) and inter-seru system balancing (Inter-SSB) to evaluate the two perspectives respectively. We theoretically develop the lower and upper bounds of Intra-SSB and Inter-SSB respectively. In addition, we define and formulate the seru system balancing problem (SSBP) as a bi-objective model with maximizing Intra-SSB and Inter-SSB simultaneously. The property of solution space for SSBP is analyzed. Finally, we develop an improved algorithm based on ε-constraint for SSBP. The algorithm saves computation time by cutting non-Pareto-optimal solutions before performing ε-constraint.