Grouping and sequencing of machining operations for high-volume transfer lines

Transfer lines are employed for the mass production of fixed products or a very narrow range of product variants. This paper considers a simple transfer line balancing problem (TLBP) with a focus on process planning and line configuration. The design features of the product are grouped and machining operations are sequenced in an optimal manner. The objective is to minimise the handling time fraction of the cycle time consisting mainly of the orientation change time and the tool change time. A new mixed integer linear programming (MILP) model is proposed to solve the problem with the aforementioned objectives while respecting a set of constraints, which include cutting tool allocation, tool magazine limit, tool life limit, takt time limit and precedence, and inclusion and exclusion constraints. Problem-specific simulated annealing algorithm (SAA) and genetic algorithm (GA) are developed. Numerical experiments are conducted to illustrate the functionality of the MILP model and heuristic algorithms with respect to optimality and the computation time.