One of the major challenges of manufacturing companies is to remain competitive in a very dynamic environment dictated by fluctuations in production rate and customer demand. These challenges may be attributed to frequent changes in customer expectations, unsteady economic conditions or failure to reach the projected throughput due to inefficiencies in production systems. Survival in such a dynamic environment is contingent on implementing manufacturing systems that are able to adapt to change quickly and economically. The U-Shaped production cell is considered to be one of the most flexible techniques for changing the number of workers in the cell to match cell cycle time to planned cycle time. However, companies currently use a trial-and-error method to develop walk-paths. It is a very iterative and time consuming process that does not always guarantee an optimal solution. Walk-paths need to be performed for all possible number of workers. Fluctuations are adapted to by altering only the number of workers and the worker’s walk-path without changing the number of stations and task allocations. Selecting the best configuration (i.e. optimal number of stations and task allocation) is dependant upon the linearity metric i.e. the measurement of the proportional throughput per worker. Designing the production cell by considering the linearity helps to keep direct labor costs per unit at a minimum for any number of workers employed. This thesis proposes a mixed integer linear model for U-shaped lines that determines the best cell configuration for various number of workers with the objective function of achieving proportional throughput per worker and decreasing the iteration time. The problem originated at Delphi Corporation but has been generalized to be applicable to other Lean systems. The model has been constructed using OPL Studio 3.7.
Library of Congress Subject Headings
Manufacturing industries--Management--Mathematical models; Industrial productivity; Just-in-time systems
Department, Program, or Center
Industrial and Systems Engineering (KGCOE)
Sudit, Moises - Chair
Erin, Reyhan, "Mixed-integer linear programming approach to U-line balancing with objective of achieving proportional throughput per worker in a dynamic environment" (2007). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus