Thesis (M.S.)--State University of New York at Binghamton, Department of Electrical and Computer Engineering, 2004. / Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 138-140). Also available in electronic version.

This research was motivated by the use of multi-track feeders in the printed circuit board (PCB) assembly. In a low volume, high mix production environment, setup time is usually considered more important than processing time. Implementation of multi-track feeders not only increases the capacity of the surface mount machines but also reduces feeder changeovers. However, improper planning could diminish these benefits. The objective of this research is to develop a process plan to minimize the feeder setups in multi-track feeder systems. Two problems have been identified: component to multi-track feeder assignment problem and PCB sequencing problem. The assignment problem is formulated as a multi-dimension symmetric assignment problem with an integer-programming model. The objective is to maximize the total similarity of the component assignment. This optimization model is implemented for small-sized problems using a commercial solver package. Due to NP-complete characteristics, heuristic algorithms are developed for solving large-scale problems and industrial cases. The Hungarian algorithm, designed for asymmetric assignment problems, is used to reduce problem size in the double feeder case. The PCB sequencing problem is solved in three stages: component and PCB grouping, intra- and inter-group PCB sequencing, and feeder setup planning. An optimal tool switch policy called Keep Tool Needed Soonest is adapted for planning the multi-track feeder setup. This research also identifies the interrelationship of the assignment problem and PCB sequencing problem. An optimal component to feeder assignment will show real advantages only when working with a well-planned PCB sequence. Data obtained from literature are used to verify the heuristic developments. The methods are also applied to industrial data for evaluation of performance of real-world problems. Experimentation is conducted with simulation data to investigate the performance of methodology for different production situations. The results show that savings of up to 85% in feeder setups can be realized with a double feeder system compared to a single feeder system, with the use of the developed methodology. The approach is also robust and efficient for different production environments. / Graduation date: 1999

Thesis (M.S.)--State University of New York at Binghamton, Dept. of Mechanical Engineering, 2006. / Includes bibliographical references.

Report (M.S.)--Virginia Polytechnic Institute and State University. M.S. 1991. / Vita. Abstract. Includes bibliographical references (leaf 105). Also available via the Internet.

Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 90-96).

This dissertation addresses the "multi-machine carryover sequence dependent group-scheduling problem with anticipatory setups," which arises in the printed circuit board (PCB) manufacturing. Typically, in PCB manufacturing different board types requiring similar components are grouped together to reduce setup times and increase throughput. The challenge is to determine the sequence of board groups as well as the sequence of individual board types within each group. The two separate objectives considered are minimizing the makespan and minimizing the mean flow time. In order to quickly solve the problem with each of the two objectives, highly effective metasearch heuristic algorithms based on the concept known as tabu search are developed. Advanced features of tabu search, such as the long-term memory function in order to intensify/diversify the search and variable tabu-list sizes, are utilized in the proposed heuristics. In the absence of knowing the actual optimal solutions, another important challenge is to assess the quality of the solutions identified by the proposed metaheuristics. For that purpose, methods that identify strong lower bounds both on the optimal makespan and the optimal mean flow time are proposed. The quality of a heuristic solution is then quantified as its percentage deviation from the lower bound. Based on the minimum possible setup times, this dissertation develops a lower bounding procedure, called procedure Minsetup, that is capable of identifying tight lower bounds. Even tighter lower bounds are identified using a mathematical programming decomposition approach. Novel mathematical programming formulations are developed and a branch-and-price (B&P) algorithm is proposed and implemented. A Dantzig-Wolfe reformulation of the problem that enables applying a column generation algorithm to solve the linear programming relaxation of the master problem is presented. Single-machine subproblems are designed to identify new columns if and when necessary. To enhance the efficiency of the algorithm, approximation algorithms are developed to solve the subproblems. Effective branching rules partition the solution space of the problem at a node where the solution is fractional. In order to alleviate the slow convergence of the column generation process at each node, a stabilizing technique is developed. Finally, several implementation issues such as constructing a feasible initial master problem, column management, and search strategy, are addressed. The results of a carefully designed computational experiment for both low-mix high-volume and high-mix low-volume production environments confirm the high performance of tabu search algorithms in identifying extremely good quality solutions with respect to the proposed lower bounds. / Graduation date: 2006

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: welding; ultrasonic. Includes bibliographical references (p. 100-101).

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