DMAIC approach to using confidence intervals to assess conformance and reduce variation in net weight for a manufactured product: a case study
Kesiena Ezewu et al.
What the paper says
Markets have become global, and economic conditions are becoming more competitive. To ensure products meet international standards, manufacturers must begin to key into the average quantity system for products released into the market. This paper demonstrates the applicability of deploying confidence intervals within a DMAIC structure to assess conformance in the net weight of a manufactured product. We applied the I-MR chart to investigate stability in the manufacturing process and used the Ishikawa fishbone diagram to improve consistency in net weight, reducing the variability from a standard deviation of 1.5 to 0.39. The percentage out of specification improved from 76.6% to 0.02%. The process capability indices Cp and Cpk improved from 0.2 to 1.32 and -0.21 to 1.25, respectively. Finally, a 97.5% confidence interval affirmed the suitability of lots for the international market in view of AQS standards as demanded by the government and international regulatory agencies.
2 citations
Evidence weight
Balanced mode · F 0.40 / M 0.15 / V 0.05 / R 0.40
| F · citation impact | 0.24 × 0.4 = 0.09 |
| M · momentum | 0.55 × 0.15 = 0.08 |
| V · venue signal | 0.50 × 0.05 = 0.03 |
| R · text relevance † | 0.50 × 0.4 = 0.20 |
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