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Technological and strategic developments have changed the role of human operators in the manufacturing environment. The highly specialized work force of the low-tech manufacturing system has evolved into the multi-functional work force of the high-tech manufacturing system. Among the multiple tasks that an operator is expected to conduct in advanced manufacturing systems (AMS) are job scheduling, inventory planning, machine set-up, problem solving, and quality inspection. The quality inspection task in AMS consists of a search component, frequently conducted by a machine, and a decision making component conducted by the operator. This quality inspection system is often referred to as a hybrid inspection system (HIS). It has been demonstrated that in general the performance of HIS is better than that of pure human or pure automated inspection systems. This research investigated the effects of different types of defects (presented at the same time in the inspected parts), multitasking (concurrently conducting independent tasks), and their interaction on the operator's performance in the quality inspection task (with a memorized quality criteria) in an AMS. The results indicate that the performance of the operator in the quality inspection task while multitasking in an AMS will be determined not only by the variety of defects that can be present in the inspected parts, but also by the mental processing resources required to meet the demand imposed by the multiple independent tasks and the memorized quality criteria. The best performance will be obtained when the additional tasks' load minimizes the monotony of the quality inspection task without interfering with the processing resources needed for the memorized quality criteria. / Ph. D.

The purpose of this research was to investigate the potential application of additive friction stir deposition (AFSD) to repair corroded steel bridge members. AFSD is an emerging solid-state additive manufacturing (AM) technology with many advantageous qualities such as low porosity, low residual stresses, flexibility in material, and a high build rate allowing for large-scale deposits. Two parameters were studied to understand the quality of AFSD on corroded steel: surface roughness and surface cleanliness. Three rounds of depositions were done: AerMet100, a high-strength corrosion-resistant steel, deposited onto AISI 1018 plates, with varying degrees of section loss, sectioned from a bridge taken out-of-service; AISI 1018 steel deposited onto an A572 Gr. 50 plate with 12 holes of varying diameters and depths drilled into the plate to simulate surface roughness; and AISI 1018 steel deposited onto an A572 Gr. 50 plate with mill scale, corrosion, and an industrial three-coat bridge paint system. The repair quality of each deposition was studied using scanning electron microscopy, microhardness testing, and three-point bending. Results from these tests indicated the following: AFSD can sufficiently mix dissimilar steels and result in a fine-grained microstructure; depositing onto a rough surface appeared to aid bonding between the two materials with little to no adverse effects on the repair quality; and finally, depending on the chosen deposition parameters, AFSD can mix foreign surface material into the matrix or mechanically remove the bulk of the foreign surface material appearing to clean the surface during the deposition. / Master of Science / This research investigated the applicability of additive friction stir deposition (AFSD) to repair corroded steel bridge members. AFSD is an emerging technology that can deposit metals without melting and build a part layer by layer similar to 3D printing. Since this process uses relatively low temperatures, the deposited material is not melted thus reducing issues associated with rapid solidification of melted metal. Three studies were conducted to better understand the print quality of AFSD on corroded steel. First, steel was deposited onto a surface with varying sized holes drilled to different depths meant to simulate a corroded surface. Second, a high-strength corrosion-resistant steel was deposited onto a corroded steel plate cut from an old bridge. Last, steel was deposited onto a steel plate with varying prepared surfaces including paint and corrosion. The quality of the depositions was studied through microscopy and mechanical testing. Results from these tests indicated the following: AFSD can sufficiently bond two different types of steels; depositing onto a non-level surface appeared to aid bonding between the two steels; and finally, AFSD can deposit steel onto certain unclean surfaces.

No / The performance of manufacturing systems needs to be continuously reviewed in response to increasingly evolving market conditions. In recent years, a large volume of research has concentrated on improving manufacturing performance. Some research has been directed at senior management emphasising the strategic need for change and how to initiate change; other research has been directed at shop floor level and the provision of tools for continuous improvement; whilst more recent research has focused on business process re-engineering and supporting methodologies. However, there is a very limited set of tools available for middle managers to encapsulate the aspirations of senior management (e.g. the strategic objectives of a company) and translate these into shop floor actions. This paper proposes a methodology to support management of the introduction of new processes, products and systems and to improve the performance of manufacturing systems. The paper presents a case and methodology for an integrated system for strategic, tactical, operational and project planning. The proposed methodology is based on structured systems analysis and simulation of a manufacturing plant. Feasibility of the approach is demonstrated through application to two small to medium-sized enterprises.

Thesis (M.B.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2999-01-01

<div>With the growing importance of the manufacturing sector, there is a tremendous demand for finding innovative ways to design manufacturing systems. Although several design methodologies are available for devising the manufacturing systems, most of the changes do not sustain for a longer period. Numerous elements contribute to issues that impede sustainability in manufacturing industries, such as the common design approach of applying solutions without understanding system requirements and appropriate thinking processes. </div><div>With a Sustainable Manufacturing System Design Decomposition (SMSDD), the precise pitfalls and areas of improvement can be well understood. </div><div>The SMSDD fosters members in the organization to collectively map the customer’s needs, identifying the requirements of the system design and the associated solutions. In this thesis, SMSDD is developed to design manufacturing systems for maximizing the potential of an enterprise to create an efficient and sustainable manufacturing system. </div><div> </div><div>In addition to being able to design new manufacturing systems or to re-design existing manufacturing systems, the SMSDD provides a potent tool to analyze the design of existing manufacturing systems. SMSDD uses the Collective System Design Methodology steps to design a manufacturing system for leading to efficient and sustainable manufacturing system. Therefore, SMSDD can apply to a broad range of manufacturing systems. </div><div><br></div>

Master of Agribusiness / Department of Agricultural Economics / Ted C. Schroeder / The CNH Wichita Product Center has had a chronic leak problem with the Skid Steer Loaders. The objective of this project was to analyze the manufacturing plant leak data and make improvements to correct the issue. The objective is twofold: 1) to make process or design improvements on current products produced in the plant and 2) to make recommendations for future designs to prevent such leak issues from reoccurring. The manufacturing data had to be transformed into usable form and then it was analyzed mostly by utilizing Pareto Charts. The highest six problem leak points were chosen from the manufacturing data. Process changes were implemented on these particular leak joints and the results were analyzed using two proportions hypothesis tests. The process changes reduced the leak rate by an average percent reduction of 86 percent. The process changes implemented will also be applied to other similar joints, and results documented in the future. The future design recommendations made from the analyzed data included the increased use of o-ring face seal connections at certain locations and where possible, reducing the number of joints per machine.

Published Article / e-Manufacturing means the fast, flexible and cost-effective production of parts directly from electronic data, which can include rapid prototyping, rapid tooling, (spare) parts on demand etc. Especially interesting is the direct manufacture of enduse parts. In this paper, recent case studies will be presented showing commercial e-Manufacturing projects including small production batches and mass customized series production from various industrial branches. The paper also discusses the relevance of several recent technological innovations in laser-sintering for e- Manufacturing, especially how increasing the productivity of machines and process chains has increased the range of applications which are cost-effective using lasersintering. <br>Case studies include: <ul> <li> small series production (up to a few thousand p.a.) of products</li> <li> production of customized (one-off) products</li> <li> mass production of customer-specific (mass customized) products</li> <li> optimized tooling concepts for production of up to millions of products</li> </ul>

During past decades manufacturing companies started opening new plants and transfer their manufacturing to other countries in order to increase their competitiveness in the market. An important area in today’s complex business environment became manufacturing location decisions that have a direct impact on companies’ future success. Many scholars introduced suggestions in what factors should be considered in manufacturing location decisions when opening new plants. However, less research has been done by identifying what critical factors should be considered in manufacturing reallocation[1] decisions when a company operates within a manufacturing footprint and intends to move manufacturing activities between existing plants. In order to fulfil this gap the study was conducted by developing a conceptual framework for supporting manufacturing reallocation decisions. The main factors, evaluation and effects were explored. In order to conduct the study three cases were analysed in two Swedish manufacturing companies, where one of the companies was currently executing a manufacturing reallocation to another plant. It was found that sometimes companies are forced to reallocate manufacturing unwillingly due to currency value changes or local governmental regulations. A tendency was noticed that some of the factors are considered at the strategic level and some are left to be handled at the operational level. However, operational level factors have a great impact on the long term strategy and future costs and should be included when making manufacturing reallocation decisions. The evaluation of factors is mostly based on assumptions and intuition. Only evaluations of economic factors are based on facts. Improvements of economic factors’ evaluations could be made by closer collaboration between plants and involvement of the right people at the right time during data collection before making a decision. Manufacturing reallocations could have effects on the sending plant and long term strategy that increases the importance to include it during decision making since hidden costs and future risks could be prevented. Finally, the conceptual framework for manufacturing reallocations is presented that could be used as a support for manufacturing reallocation decisions. [1] to assign or allot to a different place from the one originally intended.

The motivation of this research is the need for reducing time and cost associated with maintaining information and communication technology infrastructure for design and manufacturing in digitally networked environments, enhancing design communication and collaboration in distributed and collaborative design processes, and adapting to rapidly changing market demands. The objective of this dissertation is to propose a new design and manufacturing paradigm, namely, Cloud-Based Design and Manufacturing (CBDM), for enhancing collaborative product development in distributed settings. In this dissertation, the following challenges pertaining to CBDM are addressed: the systematic development of a conceptual framework and a holistic vision for CBDM systems; the development of a new approach for visualizing distributed and collaborative design processes, measuring tie strengths in a complex and large design collaboration network, and detecting design communities with common design activities in cloud-based design (CBD) settings from a social network perspective; and the development of a new approach that helps identify potential manufacturing bottlenecks and scale manufacturing capacity in cloud-based manufacturing (CBM) settings from a manufacturing network perspective. The contributions of this dissertation are categorized in three research domains: (1) proposing the first definition, a holistic vision, and an example of application scenario for CBDM, (2) modeling and analyzing information flow in cloud-based design for improving design collaboration, and (3) modeling and analyzing material flow in cloud-based manufacturing for planning manufacturing scalability.