Thesis (Master)--İzmir Institute of Technology, İzmir,2003 / Includes bibliographical references (leaves.195-202).

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 173-179). Also available in electronic version. Access restricted to campus users.

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New product development has been considered a key success factor for today's businesses. Long term survival of many manufacturing organizations depends on how successful organizations are introducing new products to compete in existing markets or in creating new markets. Despite the importance of new product development, many manufacturing organizations face a limited understanding of the relationship between manufacturing capabilities and new product success. This study examined the relationship between manufacturing flexibility and new product performance. Eight dimensions of manufacturing flexibility and three measures of new product performance were identified and the relationships among these variables were examined. Impact of new product type, value creation mode, and manufacturing system on the relationships was also assessed. A survey of the U.S. electronic manufacturing industry was conducted. Data obtained was statistically analyzed to provide valid and reliable measures for research variables and to test the hypothesized relationships. This study supports the multidimensionality of flexibility and the existence of a hierarchy among flexibility dimensions. A suggested hierarchy of manufacturing flexibility is offered. Manufacturing flexibility was found to be more positively correlated with market success than with quality, cost or delivery. The difference between quality and cost and delivery was found to be insignificant. For more radical products, manufacturing flexibility was found to be more positively correlated with product performance. Another finding suggested that manufacturing flexibility is more positively correlated with product performance in a product focused environment than in a process focused or market focused environment. Manufacturing flexibility was found to be more positively correlated with product performance in a market focused than in a process focused environment. Another result suggested that the level of positive correlation between manufacturing flexibility and new product performance is higher in a Line Flow manufacturing system and in a Flexible Manufacturing System (FMS) than in any other manufacturing system. / Graduation date: 2004

This research focuses on supporting the formation of strategic alliances through the concept of cooperative commerce, where suppliers and buyers work together to jointly optimize their businesses. The general goal of this research is to examine existing cooperative commerce models for obstacles that would hinder their successful implementation into modern industrial applications and to address those shortcomings. Total annual cost equations are formulated to capture the joint total relevant cost of cooperative commerce business relationships. These total joint relevant cost models will include terms that capture the ordering cost, holding cost, and cost of quality, as well as any applicable investment cost for process improvements, consistent with traditional economic order quantity and economic production quantity theory. This research corrects a modeling error of Affisco, et al. (2002) that led to underestimating the effectiveness of process improvements in joint economic lot size models. In addition, the models are expanded to accommodate a full range of product quality inspection policies, from zero to one hundred percent product inspections. Furthermore, the models are modified to account for the cost of scrap generation, as well as the effects of accepting non-conforming product and rejecting conforming product during quality inspections. Once the total cost models are expanded to account for these neglected costs, the joint total relevant cost equations are minimized to find the optimal batch sizes, and the effects of each model extension on the model solution are studied. Results indicate that these extensions do have a significant impact on the model results, such as reduced optimal batch sizes and increased optimal fraction conforming product.

In this study, the machining performance of a series of commercially available coated tungsten based cemented carbides, with 55o diamond shape, were investigated during finish turning of AISI 1018 steel under dry conditions. The inserts tested had a coating of TiN, Al2O3, TiN/Al2O3 and TiC/Al2O3/TiN respectively. For comparison, uncoated cemented tungsten carbide was also tested under the same cutting conditions. The coated tools exhibited superior wear resistance over the uncoated tool. The TiC/Al2O3/TiN coated tool had the lowest flank wear due to the high abrasive resistance of the TiC layer. The Al2O3 coated tool showed superior wear-resistance over the TiN/Al2O3 coated tool due to the TiN coating that deteriorated the effect of the Al2O3 outer layer. The TiN coated tool showed the least wear resistance with respect to the other coated tools. Surface roughness appeared to increase with flank wear while oscillating for all the tested tools except for the TiN coated tool. The TiN coated tool produced a relatively consistent surface roughness that was not significantly affected by the flank wear under the conditions tested. The coated tools produced lower surface roughness compared to the uncoated tool, except for the TiN/Al2O3 coated tool, which produced considerably higher surface roughness. The reason for this however was the geometry of the chip breaker, rather than the coating materials, which produced longer chips that came in contact with the work piece during the machining process. The TiC/Al2O3/TiN coated tool produced the lowest surface roughness of all the tools tested.

Automated guided vehicles (AGVs) are widely used in container terminals for the movement of material from shipping to the yard area and vice versa. Research in this area is directed toward the development of a path layout design and routing algorithms for container movement. The problem is to design a path layout and a routing algorithm that will route the AGVs along the bi-directional path so that the distance traveled will be minimized. This thesis presents a bi-directional path flow layout and a routing algorithm that guarantee conflict-free, shortest time routes for AGVs. Based on the path layout, a routing algorithm and sufficient, but necessary conditions, mathematical relationships are developed among certain key parameters of vehicle and path. A high degree of concurrency is achieved in the vehicle movement. The routing efficiency is analyzed in terms of the distance traveled and the time required for AGVs to complete all pickup and drop-off jobs. Numerical results are presented to compare performance of the proposed model. The research provides the foundation for a bi-directional path layout design and routing algorithms that will aid the designer to develop complicated path layouts.

Reports for adult population indicate that almost 80% of the adult population has reported some form of lower back aches. Each year American workers suffer more than 300,000 lost-time injuries involving musculoskeletal disorders of the back, with the costs that run into billions of dollars. Sedentary tasks are known to be major contributing factors of back pain. Prior studies have indicated that the myoelectric activity of the lumbar region decreases when the back rest inclination of a seat increased. An increase in seat pan inclination so that it increases pressure on the leg muscles is also a cause for back pain. Seating posture is also known to be a leading cause of back pain. This study focuses on the response of the latissimus dorsi muscle in the trunk, to the backrest and seat angle inclinations for different seating postures. Twenty one participants took part in the backrest experiment. The automobile seat backrest angle was varied for two angles of 90 and 100 degrees in a one hour driving session. Ten participants took part in the seat angle experiment; the seat was set at 0 and 10 degrees for a 30 minutes session at each angle. The muscle activity of the latissimus dorsi was recorded for seating postures at each angle. Based on the electromyography data, the results of analyses of variance for mean of root mean square values for the backrest experiment (P < 0.05) showed significant change. In seat angle experiment the analysis of variation of the mean values for root mean square values at (P < 0.05) was significant. It is concluded that increased backrest and inclined seat angle decreases muscle activity in the latissimus dorsi muscle.