PurposeThe purpose of this paper is to explore Six Sigma practices in a casting industry, that could improve the green sand casting process in a foundry by reducing the casting defects. The goal was to determine which variables influenced this evolution and the relative weight of critical success factors as the methodology developed.Design/methodology/approachThe DMAIC (Define, Measurement, Analyze, Improve, and Control)‐based Six Sigma approach is implemented to improve the green sand casting process and has made the process more robust to quality variations. Analysis of various critical process parameters of the melt shop is also carried out with the help of Taguchi's method of experimental design.FindingsThe proposed techniques optimized control factors, resulting in superior quality and stability of the green sand castings process, which contributes to minimizing the casting defects and improving the Sigma level of the industry.Research limitations/implicationsThis study was carried out with some boundaries such as the number of castings of differential housings, available resources, time constraints, etc.Practical implicationsThis paper is most valuable for the foundry industry, which can avail the direct benefit of Six Sigma results from the reduction in the number of defects due to improved casting processes and dispels the myths concerning the hardly ever use of Six Sigma in the casting industry.Originality/valueThe novelty of the paper lies in conducting a comparative study on the performance of a Six Sigma project. The paper will be valuable for quality professionals and management personnel in the casting industry.
Purpose -The purpose of this paper is to identify the influencing factors which cause casting defects and determination of optimum value of factors to minimize these defects in a melt shop industry, situated in north India. Percentage contribution of these factors is also estimated to develop an empirical expression between process performance and independent input variables. Design/methodology/approach -Optimization technique for melt shop process parameters of a cast iron differential housing cover based on the Taguchi method is proposed. The focus of this paper is on the robustness of the sand casting process and the case study is based upon a leading automobile foundry industry, located in north India. Taguchi's experimental design and regression analysis techniques are used to optimize the control factors, resulting in improvement of the product quality and stability. The various confirmation tests are also carried out in the range of process parameters. Findings -The outcome of this case study is to optimize the process parameters of the melt shop process, which leads to minimizing the casting defects. The process parameters considered are: mild steel, pig iron, cast iron, ferrosilicon, lime stone, ferromanganese, cock and ferrochrome. Best proportions of charge constituents that are contributing to casting defects in melt shop are identified in the first stage. These identified factors are analyzed using "Design of Experiments" approach in the second stage. ANOVA analysis is also performed for robust design of factor values and an appropriate empirical model is formulated. Research limitations/implications -A lot of effort has been put into developing the appropriate empirical model for the automobile foundry industry but additional work may also be done for gating design of the casting industry. Practical implications -The paper shows that the process parameters of any casting industry can be optimized and casting defects in the melt shop can be identified in the first stage. Originality/value -The research findings could be applied to various manufacturing industries, especially the casting industries.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.