Browsing by Author "Vitanov, Valentin"

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    Allocation of quality control stations in multistage manufacturing systems
    (Elsevier Science B.V., Amsterdam., 2011-05-31T00:00:00Z) Shetwan, Ali G.; Vitanov, Valentin; Tjahjono, Benny
    The allocation of quality control stations (AQCS) in multistage manufacturing systems has been studied extensively over the decades. This paper reviews the existing approaches, models comparison and solution techniques applied in AQCS. The relevance of the models and the effectiveness of the inspection strategies are examined by developing a generalised model. The conducting simulation experiments show that as the number of workstation increases the processing tine to solve the problem increases significantly. This led to the development of a heuristic algorithm with local search. The performance the heuristic was compared with the optimization method based on complete enumeration method (CEM). It was found that the heuristic method can derive an acceptable solution significantly faster than the CEM. The review has shown that the most common techniques used are dynamic programming and non-linear programming. The paper suggests some biologically inspired optimisation algorithms can be of interest for further study. (C) 2011 Elsevier Ltd. All rights reserved.
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    Development of a Methodology for Joining Technology Selection based on Cost Information in the Preliminary Automotive Body-in-White Product Development Process
    (Cranfield University, 2008-09) Stahl, Jan; Vitanov, Valentin
    The substantial demand of the customer for the conservation of natural resources and of the environment puts pressure on the automotive industry to reduce fuel consumption and emissions. One response to this challenge is to reduce car body weight. Hence car body development has shown an increase in the use of light weight materials that demand new production methods and joining technologies. Accordingly car body engineers have progressively less time to assess the manufacturing cost of an increasing number of new design concepts with new material and corresponding joining techniques. A review of the pertinent literature shows that there is no established methodology enabling automotive body engineers to make a rough manufacturing cost estimate of different new design concepts in the early phase of the Product Development Process. The aim of the present thesis is to provide car body engineers with a cost estimating methodology that makes it possible for them in the preliminary phase of the design process to estimate the manufacturing cost of new design concepts more systematically, hence more reliably, thus enhancing cost reduction. The methodology is based on the notion of Standardised Working Contents, which, as fundamental units of work, enable designers to compare the financial requirements of various new design options with greater facility and greater accuracy. Furthermore the methodology identifies the most cost efficient Joining Technique combination with a high degree of reliability. Economical and technical data required for the methodology are gathered from an industrial survey in collaboration with the design, planning, finance and manufacturing departments of a leading automotive company. Dynamic Programming taken from the area of Operations Research is employed to provide the optimal Joining Technique combination in terms of manufacturing cost of the car body design concept under scrutiny. Results obtained from an automotive industrial case study confirm the effectiveness of the methodology while pointing out its limitations and possibilities.
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    Identification of the influential factors of foreign direct investment in the manufacturing sector of the United Arab Emirates
    (Cranfield University, 2004) Al-Junaibi, M.; Vitanov, Valentin
    There are many factors that may influence foreign direct investment (FDI) in a certain country. The study identifies the influential factors of foreign direct investments with an emphasis on foreign multinational companies in the manufacturing sector of the UAE. It is believed that the growing need for FDI in the global economy is what derives the interest of both foreign investors and host countries in engaging in FDl. The information sought concentrates on investigating a contemporary phenomenon within its real life context, to explore relevant issues, measures, factors and opinions. In the globalised world economy of the twenty-first century, the world market for foreign investments has become more competitive. Foreign direct investment is welcomed by countries especially developing ones. FDI can be an effective contributor not only to economic growth, but it is also important to management skills, transfers of technology and a higher standard of living. Therefore, developing countries have made considerable efforts over the past decade to improve their investment climate by offering a wide range of investment incentives. The research is sponsored by the government of the U.A.E. Therefore; it aims at helping the country to reduce its dependency on oil as the main source of national income. It aims at providing scientific and analytical material to help the country achieve its goals in expanding the manufacturing sector and attracting foreign investments to create future diversification of the economy away from oil. The first stage of the thesis is to outline the problem, and the objectives of the study, with a review of literature relevant to the subject and the impact ofFDI in the UAE. The second stage is the research methodology and collecting data needed for the research. Finally, the results are analysed and discussions are presented together with some recommendations for further research. Moreover, a number of recommendations and suggestions on policy implications were derived and presented based on the research findings. It is hoped that the outcomes of this research will provide some guidelines that will enable the UAE to become a better place for conducting businesses and a favourable destination for foreign investments.
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    Review and improve the manufacturing engineering new product introduction process -AIRBUS UK
    (2005-09-07) Shaw, Stephen; Vitanov, Valentin
    This research has developed an organisational improvement methodology for the Manufacturing Engineering (ME) New Product Introduction (NPI) process at Airbus UK. The methodology is focused on improving the management of Concurrent Engineering (CE) and team/stakeholder effectiveness through improved involvement, communication, and coordination. In the context of Airbus UK’s ME NPI process the objectives were: to examine the current process, including the monitors and controls, deployed by the ME development team to design, implement and support NPI; to map/model the ME NPI process and hence, conduct a comparative analysis with best industrial practice; and to evaluate the pragmatic options open to ME and recommend appropriate business improvements/solutions. The research showed that effective CE teams provide the main vehicle for improving product development performance, by increasing integration through improved involvement, communication, and coordination. A literature study of ‘best practices’ identified the major causes of ‘waste’ within NPI as, poor communication and poor programme management. The research also showed that process modelling not only achieves a better understanding of the processes but also serves as a tool to contribute towards the assessment of CE teams using process based analysis. It was also found that process modelling improves process management within NPI. Process modelling and analysis is applied to the ME NPI process in order that a structured and pragmatic improvement methodology can be developed. The presentation of the CE organisational improvement methodology developed by this research provides Airbus UK with a less prescriptive approach to improving their business within the ME function and area of NPI. The application of the methodology is, unfortunately, outside the time limitations of this research. However, it is widely purported by ME NPI process stakeholders, and literature, that the most significant improvements to the current process can be realised through the improvement of ‘softer’ organisational issues.