The paper titled “An analysis of task assignment and cycle times when robots are added to human-operated assembly lines, using mathematical programming models” (joint with Dimény, I; Gallina, V; Gaal, A; and Sepe, C) has recently been published in the International Journal of Production Economics.
Assembly lines are flow-oriented production systems made up by a sequence of workstations arranged along a conveyor belt. In the “progressive assembly” manufacturing process, parts flow from station to station and components are gradually assembled together to obtain the final product. The assignment of tasks to the workstations is solved by assembly line balancing (ALB) problems. At each statin a worker is performing the assigned tasks. ALB problems can be formulated as by mixed integer linear mathematical programming models (MILP).
An extension to the classical ALP problems is when the different skills of workers are considered at task assignment. In this paper the possibility of the application of robots at the different stations is investigated. Robots are considered as workers with special skills, and the collaboration possibility of a robot and a worker at stations are also considered.
When workers and robots may collaborate at stations task assignment problem must be completed with the scheduling of task as well. This way the applied mathematical problem will be non-linear. The presented paper shows, how this type of models can be linearized or solved with constraint programming. The results may assist managers to find a proper assembly line configuration when workers as well as robots are used at the line.
Koltai, T; Dimény, I; Gallina, V; Gaal, A; Sepe, C: An analysis of task assignment and cycle times when robots are added to human-operated assembly lines, using mathematical programming models, International Journal of Production Economics, Volume 242, December 2021 (In-press). https://doi.org/10.1016/j.ijpe.2021.108292