The mass customisation manufacturing (MCM) paradigm has created a problem in manufacturing control implementation, as each individual customer has the potential to disrupt the operations of production. The aim of this study was to characterise the manufacturing effects of customers’ decisions in product configuration, in order to research steady state control requirements and work-in-process distributions for effective MCM operations. A research method involving both analytic and empirical reasoning was used in characterising the distributed control environment of manufacturing systems involved in MCM. Sequences of job arrivals into each manufacturing system, due to customers’ decisions in product configuration, were analysed as Bernoulli processes. A customer model based on this analysis captured the correlation in product configuration decisions over time. Closed form analytic models were developed from first principles, which described the steady state behaviour of flow controlled manufacturing systems under generalised clearing policy and uncorrelated job arrival sequences. Empirical analysis of data sets achieved through discrete event simulation was used in adjusting the models to account for more complex cases involving multiple job types and varying correlation. Characteristic response surfaces were shown to exist over the domains of manufacturing system load and job arrival sequence correlation. A novel manufacturing flow control method, termed biased minimum feedback (BMF) was developed. BMF was shown to posses the capability to distribute work-in-process within the entire manufacturing facility through work-in-process regulation at each manufacturing system, so as to increase the performance of downstream assembly stations fed from parallel upstream processing stations. A case study in the production of a configurable product was used in presenting an application for the models and methods developed during this research. The models were shown to be useful in predicting steady state control requirements to increase manufacturing performance. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.

Transfer of information between CAD models and downstream manufacturing process planning software typically involves redundant user interaction. Many existing tools are process-centric and unsuited for selection of a "best process" in the context of existing concurrent engineering design tools. A computer based Feature-Recognition (FR) process is developed to extract critical manufacturing features from engineering product CAD models. FR technology is used for automating the extraction of data from CAD product models and uses wire-frame geometry extracted from an IGES neutral file format. Existing hint-based feature recognition techniques have been extended to encompass a broader range of manufacturing domains than typical in the literature, by utilizing a combination of algorithms, each successful at a limited range of features. Use of wire-frame models simplifies product geometry and has the potential to support rapid manufacturing shape evaluation at the conceptual design stage. Native CAD files are converted to IGES neutral files to provide geometry data marshalling to remove variations in user modelling practice, and to provide a consistent starting point for FR operations. Wire-frame models are investigated to reduce computer resources compared to surface and solid models, and provide a means to recover intellectual property in terms of manufacturing design intent from legacy and contemporary product models. Geometric ambiguity in regard to what is ?solid? and what is not has plagued wire-frame FR development in the past. A new application of crossing number theory (CNT) has been developed to solve the wire-frame ambiguity problem for a range of test parts. The CNT approach works satisfactorily for products where all faces of the product can be recovered and is tested using a variety of mechanical engineering parts. Platform independent tools like Extensible Mark-up Language are used to capture data from the FR application and provide a means to separate FR and decision support applications. Separate applications are composed of reusable software modules that may be combined as required. Combining rule-based and case-based reasoning provides decision support to the manufacturing application as a means of rejecting unsuitable processes on functional and economic grounds while retaining verifiable decision pathways to satisfy industry regulators.

Bibliography: leaves 200-207. / xi, 207 leaves : ill. ; 20 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this thesis is to design and implement the hardware mapping of critical paths of a GaAs Core Processor for a Solid Modelling Accelerator. The solid modelling accelerator is designed using GaAs/CMOS/B:CMOS unified technology. High speed GaAs technology is used in the core processor to deal with floating point intensive calculations, while CMOS technology is used where high speed outputs are not required. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1996

Thesis (M.S.)--Ohio University, June, 2004. / Title from PDF t.p. Includes bibliographical references (leaves 96-99).

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Accessibility; CAM; CAD; Integration; Fixture Design. Includes bibliographical references (leaves 108-109).gh

Dissertation (Ph.D.) -- Worcester Polytechnic Institute. / Keywords: Computer aided manufacturing planning; Object-oriented systems analysis (OSA); Feature; manufacturing resource capability; setup planning; multi-part fixture Includes bibliographical references (p.146-154).

Thesis (M.S.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (p. 112-115)

M.Sc. / Layered Manufacturing (LM), also known as "Rapid Prototyping", is that process in terms of which a computer-designed model is created layer by layer with the aid of specific LM hardware. Telemanufacturing constitutes an extension of this technology that allows remote submission of manufacturing jobs or assignments across a communication medium, typically the Internet, to be built at the manufacturing bureau concerned. The de facto standard of LM is the STL file. Simply put, this file consists of a number of triangles that are used to describe an object in its entirety. This file format has several advantages over other known formats and allows easy 2D rendering. Unfortunately, however, the limitations of the latter format outweigh its advantages. Since the entire model is described in terms of a collection of triangles, the original geometry of the model is lost. As a result, a certain level of degradation will occur, especially around curvatures in the model. Although an increase in the number of triangles around such areas will enhance precision, it will also result in a much larger STL file. Triangles that get lost somewhere inside the file could also give rise to holes, orphaned surfaces and zero-width walls in the projected object. It is vital, therefore, that the manufacturing bureau verify the correctness of the entire file before it is built in order to prevent machine time and materials from being wasted. Instead of transmitting the entire file again, the bureau could attempt automatically to correct and repair less critical errors, thereby saving valuable resources and time.

The use of CAM system to create tool s trajectories in outline of simple geometry depends directly of knowledge and ability from user in how to maintain the information and make use of available riches from these systems. The parametric program requires a solid knowledge in CN programming and the results referring to CNC machine s performance are directly connect to the way of programming to obtain these results. The aim of this study was to develop a practice s analysis between parametric program and a CAM system in a specific CNC machine, based on acting time and speed of tool s progress to each programming method. The counting of time was accomplished through CNC controller, which shows the execution time of each program from its beginning until receiving or reading the stop command. The comparison between these programming methods created results that depend of the programming way, but who receive interference of controller s technologies recourses to put in action the CNC axis machine. With these testing, it was possible to demonstrate, by means of parametric programs, an increase of 65% in performance, when compared to other programming methods. / A utilização de sistemas CAM para a geração de trajetórias de ferramenta em contornos de geometria simples depende diretamente do conhecimento e da capacidade do usuário na alimentação das informações e na utilização dos recursos disponíveis desses sistemas. A programação paramétrica exige uma base sólida no conhecimento da programação CN e os resultados que se referem ao desempenho da máquina CNC estão diretamente ligados à forma de programação para a obtenção desses resultados. O objetivo deste estudo foi desenvolver uma análise de desempenho entre a programação paramétrica e um sistema CAM em uma máquina CNC específica, com base nos tempos de execução e velocidade de avanço da ferramenta para cada método de programação. A contagem de tempo foi realizada através do controlador CNC, que indica o tempo de execução de cada programa a partir do seu início até o recebimento ou leitura do comando de parada. A comparação entre esses métodos de programação gerou resultados que dependem diretamente da forma de programação, mas que recebem interferência dos recursos tecnológicos do controlador para o acionamento dos eixos da máquina CNC. Com essas experimentações, foi possível demonstrar, através de programas paramétricos, um aumento no desempenho em até 65% quando comparado a outros métodos de programação.

M.Ing. (Engineering Management) / The growing need for customized solutions and faster product delivery obliges the product development industry to develop new strategies that can enable the rapid and flexible design of products. Several design approaches have been developed to address this issue: one such is Knowledge-Based Engineering (KBE), which is a design technique that enables the automation of the design process. This approach consists of using computational intelligence to capture the design rules related to a product family in order to generate automatically customized designs adapted to particular customer requirements. Knowledge-Based Engineering is also used to facilitate the performance of design evaluation activities such as finite element analysis (FEA) and computational fluid dynamics (CFD) as part of multi-disciplinary design optimization (MDO). The application of this approach led to impressive results mostly in the automotive and aeronautical industry. Owing to this method, some companies manage to reduce the duration of the design process by 90%. Despite the excellent results obtained through the use of Knowledge-Based Engineering, there are still very few companies that make use of this approach in their design process. The review of the relevant literature showed that the lack of a standard easy-to-use methodology of implementation is one of the major obstacles to the expansion of Knowledge-Based Engineering. The knowledge processing phase constitutes one of the main challenges of the KBE implementation process. This phase consists of extracting and documenting the knowledge embedded in the design team in order to convert it in a programming code. Available methodologies such as MOKA and KNOMAD do not seem to provide easy-to-use methods to represent the design knowledge in a form that makes it easy to be programmed. The lack of a preliminary stage that justifies the adequacy of KBE for a particular design process is also an important gap identified in the literature.This dissertation discusses a detailed method that addresses issues related to knowledge processing and suitability analysis in KBE implementation. The knowledge processing method suggested is based on the Work Breakdown Structure (WBS) which is used widely in the system engineering approach and consists of a very logical classification of the design knowledge. The strength of this method lies in its ability to represent the design knowledge in a form that makes it understandable for both engineers and programmers. Appropriate representation of this sort shortens the duration of the knowledge processing and facilitates the knowledge programming phase. Regarding the rationale for choosing of KBE, a detailed suitability assessment method is proposed.