Estimating Some Metrics in Six Sigma Through Confidence Intervals

Milan Terek (1)
(1) School of Management, Slovakia

Abstract

Purpose: This paper suggests a methodology for estimating some Six Sigma metrics using confidence intervals.


Methodology/Approach: This approach assumes that the process follows a normal distribution with a constant variance. The mean of the process is shifted from the target value to the right or left by 1.5 standard deviations. The estimates are based on a random sample of size n taken during a time when the process is stable.


Findings: The paper describes how to create confidence intervals for the number of defects per unit, the probability that a unit will be free of defects, and the rolled throughput yield.


Research Limitation/implication: We assume a discrete process in which n units of the product are selected during a time when the process is stable.


Originality/Value of paper: By applying the proposed estimation procedures, process performance evaluations can be improved, facilitating decision-making for Six Sigma projects.

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References

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Terek, M., 2023a. Charakteristiky výkonnosti procesu v metodológii Six Sigma. Slovenská štatistika a demografia, 33(4), pp. 20 – 40. Avalaible at: https://ssad.statistics.sk/SSaD/wp-content/files/4_2023/4_2023_SSaD_clanok_2_Terek.pdf.

Terek, M., 2023b: How to Estimate the Sigma Level of the Process. Quality Innovation Prosperity 27(3). https://doi.org/10.12776/qip.v27i3.1947.

Authors

Milan Terek
milan.terek1@gmail.com (Primary Contact)
Author Biography

Milan Terek, School of Management

Milan Terek, PhD. works from 2018 as a full professor at the School of Management in Bratislava (course leader on Introduction to Statistics, Statistics, Mathematics for Managers II, Quantitative Methods for Managers, Quantitative Methods in Business Management Research). Prior to this, he worked at the University of Economics in Bratislava (course leader on Statistics, Statistical Quality Control, Decision Analysis, Data Mining, Survey Sampling, Linear Programming, Nonlinear Programming, Operations Research, and System Modelling). His research activities are focused on the applications of statistical methods in economics and management. 

 

School of Management in Bratislava, Panónska cesta 17
851 04 Bratislava, Slovakia

 

e-mail: milan.terek1@gmail.com; mterek@vsm.sk

Terek, M. (2024). Estimating Some Metrics in Six Sigma Through Confidence Intervals. Quality Innovation Prosperity, 28(1), 15–25. https://doi.org/10.12776/qip.v28i1.1972

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