# title
A U-line assessment heuristic & evaluation model

# abstract
In the design of lean manufacturing systems, U-shaped manufacturing cells, also known as U-lines, have been used to address product variety, reduce worker travel distances between stations, and improve productivity levels. However, U-line machine assignments to multiple workers which balance workload are an important aspect of the manufacturing system design. Changes in product demand imply changes to the production plan that would require a rebalancing effort on multiple U-lines. In this paper, a heuristic U-line assignment algorithm has been developed to provide feasible U-line machine/operator assignments. The proposed heuristic can be used to quickly evaluate these different U-line assignment options, and balance workload between multiple cell workers to meet takt time requirements. Different U-line system operating parameters can be specified and used to assign workers to workstations. These include travel time between all possible workstations; setup, processing and inspection time at each workstation; and cells load/unload times at the input/output cell interface. The basic problem is np-hard, and increases dramatically in size as a function of the number of workstations, the number of workers and takt time goals change. The developed heuristic reaches a good feasible solution for all sized problems in a short amount of computation time.

# authorList[]
Moya, H., Curry, G. L., & Phillips, D. T.