• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.154-167
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• 2004

The TOC/DBR and Six Sigma are the most attention-getting concepts for managing manufacturing companies in Korea. Using the ideas and methods of the TOC/DBR, companies can achieve a large reduction of work-in-process and finished-good inventories, significant improvement in scheduling performance, and substantial earnings increase. The Six Sigma approach derives the overall process of selecting the right projects based on their potential to improve performance metrics and selecting/training the right people to get the business results. These two concepts have different backgrounds and different viewpoints for production systems. So, if the two concepts collaborate each other, the synergy effects to innovate production systems can be expected. This paper proposes a new approach to implement the TOC/DBR concepts in production systems. This approach uses some concepts of Six Sigma which stresses educations, project approaches (step by step procedure using a Roadmap), and improvement philosophy.

• Journal of the Korea Safety Management & Science
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• v.7 no.3
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• pp.121-135
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• 2005

The TOC and Six Sigma are the most attention-getting concepts for managing manufacturing companies. Using the ideas and methods of the TOC, companies can achieve a large reduction of work-in-process and finished good inventories, significant improvement in scheduling performance, and substantial earnings increase. The six sigma approach derives the overall process of selecting the right project based on their potential to improve performance metrics and selecting and training the right people to get the business results. These two concepts have different backgrounds and different viewpoints for production systems. so, if the two concepts integrate each other, the synergy effects to innovate production systems can be expected. The purpose of this paper suggest that integration strategy between Six Sigma and TOC for profit maximization.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.1
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• pp.49-54
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• 2010

Lean 6 sigma has recently been used to describe a management system which combines lean management and 6 sigma. The marriage between Lean manufacturing and 6 sigma has proven to be a powerful tool for cutting waste and improving the organization operations. Time and quality are the most important metrics in improving any company's production and profit performance. lean 6 sigma is a management innovation for improving production efficiency, process quality, cost reduction, investment efficiency and customer's satisfaction. in this paper, Advanced cell line is builded the home appliance goods of the LCD TV final assembly line of domestic company line, training the multi-skilled man and controlling the production information system based on Lean 6 sigma.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.293-301
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• 2013

The purpose of this study is to introduce the limit of previously used six sigma quality process evaluation metrics, $Z_{st}$ and $P_{pk}$, and a solution to overcome this drawback by using a metric based on performance evaluation of Z-factor quality innovation. Case analysis on projects from national six sigma contest from 2011 to 2012 is performed and literature review on new drug development HTS (High Throughput Screening) is used to propose innovative performance evaluation metrics. This research shows that experimental study on six sigma evaluation metric, $Z_{st}$ and $P_{pk}$, have no significance difference between industrial type (Manufacturing, Semi-Public Institute, Public Institute) and CTQ type (Product Technology Type CTQ, Process Technology Type CTQ). Following discovery characterize this quality improvement as fixed target type project. As newly developed moving target type of quality innovation performance metric Z-Factor is used for evaluating experimental study, hypothetical analysis suggests that $Z_{st}$ and $P_{pk}$ share different relationship or even show reciprocal relationship. Constraints of the study are relatively small sample size of only 37 projects from past 2 years and conflict on having interview and communication with six sigma quality practitioner for qualitative experimental study. Both moving target type six sigma innovation project and fixed target type improvement project or quality circle enables efficient ways for a better understanding and quality practitioner use by applying quality innovation performance metric. Downside of fixed target type quality performance evaluation metric, $Z_{st}$ and $P_{pk}$, is presented through experimental study. In contrast, advantage of this study is that high throughput requiring product technology, process technology and quantum leap typed innovation effect is evaluated based on precision and accuracy and Z-Factor that enables relative comparison between enterprises is proposed and implemented.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.2
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• pp.65-70
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• 2005

Those specifications of the CLIA analytical tolerance limits are consistent with the performance goals in Six Sigma Quality Management. Six sigma analysis determines performance quality from bias and precision statistics. It also shows if the method meets the criteria for the six sigma performance. Performance standards calculates allowable total error from several different criteria. Six sigma means six standard deviations from the target value or mean value and about 3.4 failures per million opportunities for failure. Sigma Quality Level is an indicator of process centering and process variation total error allowable. Tolerance specification is replaced by a Total Error specification, which is a common form of a quality specification for a laboratory test. The CLIA criteria for acceptable performance in proficiency testing events are given in the form of an allowable total error, TEa. Thus there is a published list of TEa specifications for regulated analytes. In terms of TEa, Six Sigma Quality Management sets a precision goal of TEa/6 and an accuracy goal of 1.5 (TEa/6). This concept is based on the proficiency testing specification of target value +/-3s, TEa from reference intervals, biological variation, and peer group median mean surveys. We have found rules to calculate as a fraction of a reference interval and peer group median mean surveys. We studied to develop total error allowable from peer group survey results and CLIA 88 rules in US on 19 items TP, ALB, T.B, ALP, AST, ALT, CL, LD, K, Na, CRE, BUN, T.C, GLU, GGT, CA, phosphorus, UA, TG tests in chematology were follows. Sigma level versus TEa from peer group median mean CV of each item by group mean were assessed by process performance, fitting within six sigma tolerance limits were TP ($6.1{\delta}$/9.3%), ALB ($6.9{\delta}$/11.3%), T.B ($3.4{\delta}$/25.6%), ALP ($6.8{\delta}$/31.5%), AST ($4.5{\delta}$/16.8%), ALT ($1.6{\delta}$/19.3%), CL ($4.6{\delta}$/8.4%), LD ($11.5{\delta}$/20.07%), K ($2.5{\delta}$/0.39mmol/L), Na ($3.6{\delta}$/6.87mmol/L), CRE ($9.9{\delta}$/21.8%), BUN ($4.3{\delta}$/13.3%), UA ($5.9{\delta}$/11.5%), T.C ($2.2{\delta}$/10.7%), GLU ($4.8{\delta}$/10.2%), GGT ($7.5{\delta}$/27.3%), CA ($5.5{\delta}$/0.87mmol/L), IP ($8.5{\delta}$/13.17%), TG ($9.6{\delta}$/17.7%). Peer group survey median CV in Korean External Assessment greater than CLIA criteria were CL (8.45%/5%), BUN (13.3%/9%), CRE (21.8%/15%), T.B (25.6%/20%), and Na (6.87mmol/L/4mmol/L). Peer group survey median CV less than it were as TP (9.3%/10%), AST (16.8%/20%), ALT (19.3%/20%), K (0.39mmol/L/0.5mmol/L), UA (11.5%/17%), Ca (0.87mg/dL1mg/L), TG (17.7%/25%). TEa in 17 items were same one in 14 items with 82.35%. We found out the truth on increasing sigma level due to increased total error allowable, and were sure that the goal of setting total error allowable would affect the evaluation of sigma metrics in the process, if sustaining the same process.

• Communications of the Korean Mathematical Society
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• v.29 no.2
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• pp.319-329
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• 2014

In this paper we study the properties of conformally recurrent pseudo Riemannian manifolds admitting a proper conformal vector field with respect to the scalar field ${\sigma}$, focusing particularly on the 4-dimensional Lorentzian case. Some general properties already proven by one of the present authors for pseudo conformally symmetric manifolds endowed with a conformal vector field are proven also in the case, and some new others are stated. Moreover interesting results are pointed out; for example, it is proven that the Ricci tensor under certain conditions is Weyl compatible: this notion was recently introduced and investigated by one of the present authors. Further we study conformally recurrent 4-dimensional Lorentzian manifolds (space-times) admitting a conformal vector field: it is proven that the covector ${\sigma}_j$ is null and unique up to scaling; moreover it is shown that the same vector is an eigenvector of the Ricci tensor. Finally, it is stated that such space-time is of Petrov type N with respect to ${\sigma}_j$.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.337-348
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• 2015

This research introduces the Financial Effect Measurement (FEM) models which measures both the improvement and the innovation performance of Quality Control Circle (QCC) and activities of Six Sigma. Concepts and principle of Comprehensive Income Statement (CIS), Balanced Scorecard (BSC), Time-Driven Activity Based-Costing (TDABC) and Total Productive Maintenance (TPM) are applied in order to develop the 4 FEM models presented in this paper. First of all, FEM using CIS depicts the improvement effects of production capacity and yield using relationships between demand and supply, and line balancing efficiency between bottleneck process and non-bottleneck processes. Secondly, cause-and-effect relation of Key Performance Indicator (KPI) is used to present Critical Success Factor (CSF) effects for QC Story 15 steps of QCC and DMAIC (Define, Measure, Analyze, Improve, and Control) of Six Sigma. The next is FEM model for service management innovation activities that uses TDABC to calculate the time-driven effect for improving the indirect activities according to the cost object. Lastly, FEM model for TPM activities presents the interpretation of improvement effect model of TPM Capital Expenditure (CAPEX) and Operating Expenditure (OPEX) maintenance using profit, cash and Economic Added Value (EVA) as metrics of enterprise values. To better understand and further investigate FEMs, recent cases on National Quality Circle Contest are used to evaluate new financial effect measurement developed in this paper.

• Journal of the Korea Safety Management & Science
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• v.7 no.4
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• pp.141-163
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• 2005

The international SPICE (Software Process Improvement and Capability determination) Project ISO/IEC 15504(SPICE : Software Process Improvement and Capability determination) is an emerging International Standard on SPA(Software Process Assessment). A prime motivation for developing this standard has been the perceived need for an internationally recognized software process assessment framework that pulls together the existing public and proprietary models and methods. A SPICE assessment can be considered as one of representative SPA model since assessors assign ratings to indicators and metrics to measure the capability of software process. But this models doesn't provide a systematic measurement procedures and dynamic method for SPI(Software Process Improvement). Through the evaluation of SPICE is capable of providing a substantiated basis for using the notion of capability, as well as providing information for nacessary improvements to the standard using 6sigma process. As a result, this paper propose a measurement procedure and guidelines for application of 6sigma process to guarantee the reliability in SPI and suggest the structure to support SPI on overall organization.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.4
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• pp.49-63
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• 2020

Municipal governments today are facing increasingly complex issues while resources continue to be constraint but the service quality expectation from citizen is more demanding. They must develop and implement tools that help manage operations more efficiently. While Lean Six Sigma principle and tools have been widely applied to profit organizations, the extant literature has not provided many cases of such application to local governments. This research presents a case study of applying Lean Six Sigma approaches and tools to a municipal government of a small town in USA to improve process efficiency, quality performance, and citizen satisfaction. In this case study, DMAIC (Define, Measure, Analyze, Implement, and Control) is used as a tool to define current issues, develop, and measure performance metrics, and recommend action plans. The result of this case study shows that applying the principles and tools of Lean Six Sigma provides an excellent way to improve the process efficiency and quality of providing public work services at a local government.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.374-380
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• 2015

As semiconductor devices are being scaled down, random variation becomes a critical issue, especially in the case of static random access memory (SRAM). Thus, there is an urgent need for statistical methodologies to analyze the impact of random variations on the SRAM. In this paper, we propose a novel sampling method based on the concept of a confidence ellipse. Results show that the proposed method estimates the SRAM margin metrics in high-sigma regimes more efficiently than the standard Monte Carlo (MC) method.