Theses & Dissertations

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https://hdl.handle.net/20.500.14170/1590

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Browsing Theses & Dissertations by Subject "Aerospace"
  • Publication
    Quality improvement at the trimming process of a composite manufacturing firm: investigation and implementation
    ( 2020)
    Ahmed Mohamed Ahmed Mohamed Elradi
    Aircraft composite parts are manufactured to fulfil high levels of performance under demanding conditions. The aerospace manufacturing industry uses sophisticated composite materials, in line with increasing global demands. There are two main causes that lead to the need for high quality incoming materials in industry, and they are expensive raw materials and the complexity of the manufacturing process that the incoming materials are going to be subjected to, which may lead to high failure rates. To add, many raw materials used in the industry have short lifespan and a wide range of inconsistent manufacturing conditions. Hence, the most appropriate inspection techniques tooling, manufacturing systems, and automated structures are required. This study is carried out in an aerospace composite manufacturing plant, specifically at the Trimming Process where composite panels are produced. There are three main phases of the study, each corresponding to the three objectives of the work. The first phase is to identify the causes that lead to workers making frequent mistakes in the production line, while the second phase is to implement a suitable technique for improvement on the shop floor. The technique is called ‘FaRSLeSS’ (Failure Rate Reduction and Sustainability through Lean and Six Sigma), whereby, some versions of it have already been successfully implemented at other work stations in the company. The third phase of the research is to develop a way to incorporate the outcome of Objective 2 so that the improvement seen can be made sustainable on the manufacturing shop floor. To achieve Objective 1, a questionnaire is developed and distributed to the workers at the Trimming Process. It is found that the workers need more training on trimming methods and general manufacturing lean concepts in order to do well in their work, which is predominantly done manually. The second objective, which is to develop the appropriate FaRSLeSS technique and to implement it on the Trimming Process, has shown that improvement, in the form of reduction of defects, is possible. Collection of data at two points in time (Point 1 is ‘before’ while Point 2 is ‘after’ a series of discussions with workers on the shop floor) show that FaRSLeSS has a high potential of enabling improvement if used on a full scale. For this, data is collected and then fed into Pareto Charts and Cause-and-Effect Diagrams, and a movable table is designed to be used to aid in the movement of panels from one location to another so as to minimize knocks and bumps that would lead to defects of the panels. To add, a training program is developed and partly implemented on the workers. Lastly, institutionalization of the amendments is proposed to ensure sustainability of the improvement at the Trimming Process.
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