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Controlling the process variations on the perimeter of a component to the targeted mean in milling is a huge challenge. Several factors such as spindle speed, feed rate, depth of cut, etc. affects this process variation. In this paper, spindle speed and feed rate are considered. Aluminum alloy 6061 widely used materials in aircraft, automobile and helicopter components is selected for this study. A full factorial design of experiment is carried out with five levels. Three different machining conditions: machining 2 mm thickness, machining 3 mm thickness and machining 4 mm thickness are considered. The objectives of the study are: (a) to determine the optimum cutting parameters to minimize the process variations found on the perimeter of the work piece;' (b) to determine which machining condition provides least process variations. To achieve this, 25 different combinations of experiments are conducted under each machining condition. Thus, a total of 75 experiments are carried out. Non-contact laser detection system is used to collect the real-time machining data. Two-way ANOVA is used to analyze the data. The results found that (a) both spindle speed and feed rate are significant over the process variations on the perimeter of a component; (b) feed rate is more significant on the outcome when compared to spindle speed; (c) process variations found on the perimeter of the component size 2 mm thickness are more when compared to a component size 4 mm thickness; and (d) mathematical models are derived for determination of optimum cutting parameters to achieve tighter process variations.

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Lean Six Sigma is a disciplined data driven approach to improve the quality and the performance of a process or a system with which finally results to the profitability of a firm. Many of the organizations have adopted Six Sigma methodology to improve their quality and their performance to competitive industrial world. This work is concentrated with one of the leading Automotive component manufacturing company in South India. The main objective of this paper was to reduce the product defect with the application of Lean Six Sigma methodology. The paper follows the DMAIC methodology to investigate defects and its root causes and provide a solution to reduce and/or eliminate these defects. This paper also explores how a manufacturing process can use a systematic methodology to move towards world-class quality level.

A component in machining is accepted when the dimensions are within the tolerance specifications. In aircraft components machining, controlling the weight of the components is of high importance. In this paper, a new concept called near minimum material zone was introduced, which would address the control of the weight of the aircraft components in machining. To prove this concept, two sets of experiments with 20 samples were conducted using Deckel Maho CTX310 ECO VI CNC machine. The first experiment was conducted with normal machining processes. The second experiment was conducted using a new concept. Lean Six Sigma DMAIC methodology was adopted for this study. Several Six Sigma tools such as process capability analysis (Cp, Cpk), cause and effect diagram, X Hi/Lo and R-charts, etc. were used. The paper suggests that this new concept not only helped to control the weight of the aircraft components but also improved the desired quality by minimizing the dispersion of the component dimensions to obtain higher sigma level.