| Largely due to pressures of just-in-tithe (JIT) manufacturing, many assembly lines are now being designed as U-shaped assembly lines. When compared to straight lines they typically have, better balancing, improved visibility and communications, fewer work stations, more flexibility for adjustment, minimization of operation travel, and easier material handling.; Single model and mixed model straight line assembly line balancing have been thoroughly researched since the first published work in 1955. However, the first published work on U-shaped lines was not until 1994. In comparison to the well studied straight assembly line balancing problem, there are many areas in U-shaped assembly line balancing which require further research. The present work attempts to fill current research voids in the area of U-shaped assembly line balancing by addressing several new areas including parallel stations and mixed product lines.; A new optimal solution algorithm for simple U-shaped Line assembly line balancing is developed. A significant focus of the algorithm is the use of multiple lower bounding algorithms and a new heuristic to achieve tight upper bounding. Both the optimal solution algorithm and the imbedded heuristic solution are shown to be improvements to current algorithms.; U-shaped assembly line balancing with parallel stations is introduced. In the U-shaped assembly line balancing with parallel stations problem, the stations of the simple U-shaped problem are replaced with stages consisting of one or more stations in parallel. A mathematical model, heuristic and optimal solution algorithms, and results are presented.; Mixed model U-shaped assembly line balancing is introduced. Like U-shaped assembly line balancing with parallel stations this breaks new research ground. A mathematic model, a heuristic solution methodology, and results are presented. |
