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The need for a product model which can support the modelling requirements of a broad range of applications leads to the application of a feature-based model. An important requirement in feature-based design and manufacture is that a single feature representation should be capable of supporting a number of different applications. The capability of representing products composed of assemblies is seen to be necessary to serve the information needs of those applications. To achieve this aim it is an essential prerequisite to develop a formal structure for the representation of assembly information in a feature-based design system. This research addresses two basic questions related to the lack of a unified definition for features and the problem of representing assemblies in a feature-based representation. The intention is to extend the concept of designing with features by incorporating assembly information in addition to the geometrical and topological details of component parts. This allows models to be assembled using the assembly information within the feature definitions. Features in this research are defined as machined volumes which are represented in a hierarchical taxonomy. The taxonomy includes several types and profiles of features which cover a general range of machined parts. A hierarchical assembly structure is also defined in which features form basic entities in the assembly. Each feature includes information needed to establish assembly relationships among features in the form of mating relationships. An analysis of typical assemblies shows that assembly interfaces occur at the face level of the mating features and between features themselves. Three mating relationships between pairs of features have been defined (against, fits and align) and are represented in the form of expressions that can be used for evaluations. Various sub-types of these major mating relationships can be identified (e.g. tight fit, clearance fit, etc.) and represented through the use of qualifying attributes. Component Relation Graphs, Feature Relation Graphs and Face Mating Graphs have been developed to represent each level of interaction in an assembly, and assembly relationships are combined with knowledge on process planning into a Component Connectivity Graph. These graphs are used as the basis for deriving an integrated data structure which is used for defining classes for each level in the assembly hierarchy. The implementation of a prototype system has been facilitated by use of an object-oriented programming technique which provides a natural method of adding functionality to the geometric reasoning process of features and the complex relationships between the parts that make up the assembly. The feature-based model is embedded in an object-oriented solid modeller kernel, ACIS®. The research demonstrates the possibilities for a single feature representation to support multiple activities within a computer integrated manufacturing environment. Such a representation can form the basis of design improvement techniques and manufacturing planning as well as be a model to support the life cycle of the product.

Thesis (PhD)--University of South Australia, 1996

Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xii, 264 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 157-167).

Thesis (Ph.D.)--West Virginia University, 2007. / Adviser: B. Gopalakrishnan. Includes bibliographical references.

Thesis (M.S.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: Shi-Jie (Gary) Chen. Includes bibliographical references (leaves 89-99).

Principles of concurrent development are applied to the design of a small-scale device for converting natural gas or liquefied petroleum gas into hydrogen. The small hydrogen generator is intended for serial production for application in the production of industrial hydrogen, fueling stationary fuel cell power systems and refueling hydrogen-fueled fuel cell electric vehicles. The concurrent development process is contrasted with the traditional, linear development process for petrochemical systems and equipment, and the design is benchmarked against existing small hydrogen generators as well as industrial hydrogen production apparatus. A novel system and hardware design are described, and a single cycle of concurrent development is applied in the areas of catalyst development, thermodynamic optimization, and reactor modeling and design. The impact of applying concurrent development techniques is assessed through economic modeling, and directions for future development work are identified. / Ph. D.

Nowadays in a turbulent market, developing and launching a new product is one of most competitive strategies implemented by many large and small enterprises. In fact, launching a new product depends upon the performance of four critical functions: design, manufacturing, distribution and marketing. Their performances would increase or decrease the total time-to-market and consequently time-to-money. Time-to-market would be improved if the manufacturing system can diminish time-to-volume/quality/cost during production start-up phase. In order to overcome the impediment during a start-up phase, the significant parameters which are influencing a production start-up phase should be identified and managed. Hence, a system-wide approach would facilitate a product realization process so as to achieve global optimization throughout the entire process. One of such systems is Concurrent Engineering which can be applied owing to being enable to choose the best practice to improve product introduction process, being capable to improve cross functional integration and communication, and being empowered to apply a set of comprehensive methods for design analysis so that designers can select the most optimal design solution which is not only considering the design constraints, but also taking the constraints of production system, logistics and distribution into account. Hence, it can cover majority of problems in start-up phase which are generated due to lack of empathy between design and manufacturing. This research studied the significant parameters influencing a production start-up phase. Then, it investigated whether the principle of concurrent engineering would support an efficient start-up phase. The selected research methodology is based on a conceptual and supportive literature review of the current scholars. The research design is according to a three-step process which is applied to catch most relevant literatures. The research implements an analogy reasoning logic to establish the outcome of the research through the comparison between principles of a concurrent engineering program and significant parameters. As a result of the research, the significant parameters are identified, in addition, a managerial framework is structured that can present the requirements to manage an efficient start-up phase. Moreover, the results indicate how a concurrent engineering program would support a start-up phase.

Oftast har produktutveckling samma generella tillvägagångssätt: En specifikation för en ny produkt lämnas från en marknadsföringsavdelning till en produktutvecklingsavdelning. Produktutvecklare tar sedan fram koncept som utvecklas till prototyper för att sedan tillverkas och säljas. Tillvägagångssättet skiljer sig vanligtvis genom att olika modeller som exempelvis Lean product development eller integrerad produktutveckling används i processen. Delen av Lean product development (LPD) som används vid konceptutveckling kallas set based concurrent engineering (SBCE) och dessa begrepp är relativt nya i Sverige. Vad krävs för att arbeta med set based concurrent engineering på ett framgångsrikt sätt? Går det att identifiera viktiga faktorer vid produktutveckling med SBCE hos företag? En litteraturstudie som resulterade i en lista med fem potentiellt viktiga faktorer vid produktutveckling med SBCE gjordes inför en kvalitativ studie av fem företag. Semistrukturerade intervjuer utfördes på Husqvarna, Saab, Furhoffs, Ericsson Radio och GKN Aerospace för att samla in empiri inför analys. I analysen jämfördes företagens sätt att produktutveckla med listan som togs fram i litteraturstudien. Slutsats av studien var att några viktiga faktorer för att lyckas med produktutveckling enligt SBCE är: Bred lösningsrymd, Kunskapsbaserat bortval av koncept, Återvinning av kunskap, Tekniskt kunnig projektledning, Tvärfunktionella arbetsgrupper. Dessutom framkom att en investering i rätt ledarskap kan vara en viktig faktor vid implementering av SBCE då företagets ledning måste ha förståelse för arbetsmodellen om SBCE ska kunna resultera i en positiv effekt. / Product development usually has the same general approach: A specification for a new product is provided to the product development department from the marketing department. Product developers then generate concepts which are developed into prototypes before the products are manufactured and sold. The procedure usually differs by the use of different models such as Lean product development or integrated product development in the process. The part of Lean product development (LPD) that is used when developing concepts is called set based concurrent engineering (SBCE) and these are new concepts in Sweden. What is required to work with set based concurrent engineering in a successful manner? Is it possible to identify important factors when developing products using SBCE in companies? A literature study which resulted in a list with five potentially important factors when developing products using SBCE was created before a qualitative study was conducted at five companies. Semi structured interviews were conducted at Husqvarna, Saab, Furhoffs, Ericsson Radio and GKN Aerospace to gather data for an analysis. In the analysis, comparisons were made between the companies’ way of developing products with the list that was created in the end of the literature study. A conclusion of the study was a number of important factors when developing products using SBCE could be: Wide solution space, Knowledge based screening of concepts, Recycling of knowledge, Technically competent project management, Cross functional teams. The study also showed that an investment in the right type of leadership could potentially be an important factor when implementing SBCE since the company management need to understand the working model if SBCE is going to have a positive effect.

D.Ing. / A development model for complex products in a multi-disciplinary development environment, is the focus of this research. Currently there are a few development models in use in industry, however it is shown in this research that these models are based on one or at best two development criteria, for instance TQM focuses on quality but the other development criteria do not feature strongly in TQM. The aim of this research is to develop a generic model for the development of complex, multi-disciplinary products, such as missiles, that have at least mechanical and electronic engineering involvement. The researcher presented a rationale and a problem statement as the starting point of the research. The problem being the scarcity of a development model that includes the TRAMM development criteria into the early stages of development in a multi-disciplinary environment for complex products. The problem statement stipulated the environment and the research essence. The need for a development model that includes TRAMM in a multi-disciplinary development environment for complex products is emphasised. The research objectives and the main definitions used in this research are given. The TRAMM criteria are clearly defined. The TRAMM criteria were emphasised. Currently these development criteria are each researched in an isolated, specialist field. It is shown that not all the TRAMM criteria are included in the current development models. However, the TRAMM criteria as isolated development criteria are fields well documented except in a methodology on how to implement these in the early stages of development. The TRAMM criteria are currently add-on development. The intention with this research is to integrate the TRAMM criteria into the early stages of the development. The researcher gives the possible methodology to include the TRAMM criteria in a development model. The current development models are introduced. The investigated development models are DFR/DFM, IPD, TQM and CE. The strong and weak characteristics of each model are highlighted. A possible methodology on how to incorporate the strong development criteria of the specific model in an integrated development model. The five development phases of the MPS development model are discussed. The MPS development model consists of a number of modules that are used for certain development tasks within the global development process. The contingency and processes of this modular model are one of the major problems. An integrated development model should solve this problem. The MPS development model is the basis for the IPS model. Two product developments based on the MPS model are identified and discussed. During the development of these products, requirements were raised and further development criteria were identified and included in the MPS development model. The development criteria that are introduced in these two developments are highlighted and possible methods on how to include it in an integrated model are discussed. Summaries of four of the literature-surveyed models are ascertained before it is evaluated. An evaluation matrix consisting of 84 development criteria is proposed. This matrix is based on the literature-survey and the current development models. This matrix includes development criteria from these models. The matrix incorporates the TRAMM criteria, management, design, organisation and project policies. The matrix makes a comparison between the different development models including the MPS model. It is clear from the comparison that the different models were developed with a certain aspect of development in mind. These models do not include all the development criteria given in the 84 criteria evaluation matrix. A model is proposed that includes these criteria and that can be tailored according to certain user requirements. An integrated model that includes the criteria given in the evaluation matrix, which includes the TRAMM criteria, is required. Such a model is proposed. This model is named the IPS development model. The IPS development model for development in a multi-disciplinary environment is described. This model is based on the MPS and literature-surveyed development models. From the evaluation matrix, it is clear that some of the criteria are not included in any of the literature-surveyed models or the MPS development model. The inclusion of these criteria in the IPS model is part of the contribution of this research. The research contributions are highlighted. The IPS development model is a model for development in a multi-disciplinary environment for complex products. It can be tailored for various fields including mechanical and electrical development fields. The IPS model concentrates on a 5-phase development structure. This structure concentrates on the management aspects of development. Once the management phase (phase 0) is in place, the development can start. This phase is called the concept, exploration and definition phase (phase 1). During this phase the concepts are explored and defined. In phase 1, no hardware is built. Hardware that demonstrates new technology or reduces design risk is the only exception to this rule. If all the concepts are explored, the demonstration and validation phase (phase 2) can start. The demonstration and validation phase includes the TRAMM criteria of the development. Phase 3, the full-scale engineering development phase is the phase where the hardware is designed and this phase includes the design aspects of the development. Phase 3 is the last phase covered in this research; the other two phases are the production, commissioning and support phases. These phases are included as the framework for the feedback path of the development. The IPS development model is circulated in one of the intended development environments and evaluated. The respondent's results show that most of the criteria in the evaluation matrix are significant the development. On an average scale, the TRAMM criteria are regarded as more than 75% important in this specific multi-disciplinary development environment.