Six Sigma: Definition and underlying theory

Six Sigma has been gaining momentum in industry; however, academics have conducted little research on this emerging phenomenon. Understanding Six Sigma first requires providing a conceptual definition and identifying an underlying theory. In this paper we use the grounded theory approach and the scant literature available to propose an initial definition and theory of Six Sigma. Our research argues that although the tools and techniques in Six Sigma are strikingly similar to prior approaches to quality management, it provides an organizational structure not previously seen. This emergent structure for quality management helps organizations more rigorously control process improvement activities, while at the same time creating a context that enables problem exploration between disparate organizational members. Although Six Sigma provides benefits over prior approaches to quality management, it also creates new challenges for researchers and practitioners.     

The effects of Six Sigma on corporate performance: An empirical investigation

The purpose of this study is to investigate the impact of adopting Six Sigma on corporate performance. Although there is a fairly large and growing body of anecdotal evidence associated with the benefits of implementing Six Sigma, there is very little systematic and rigorous research investigating these benefits. This research extends previous research in several important ways including utilizing a sample of 84 Six Sigma firms that represent a wide variety of industries and firm characteristics, utilizing rigorously constructed control groups to ensure the validity of our comparisons and conclusions, and investigating the impact of adopting Six Sigma on corporate performance over a ten year period. To carry out this investigation, the event study methodology is employed. The ten year period consists of three years prior to Six Sigma implementation, the event year corresponding to the year Six Sigma is adopted, and six years post Six Sigma implementation. To assess the impact of adopting Six Sigma on corporate performance we utilize commonly used measures including Operating Income/Total Assets (OI/A), Operating Income/Sales (OI/S), Operating Income/Number of Employees (OI/E), Sales/Assets (S/A), and Sales/Number of Employees (S/E). The sample Six Sigma firms are compared to different benchmarks including the overall industry performance and to the performance of carefully selected portfolios of control firms. The results of the study indicate that adopting Six Sigma positively impacts organizational performance primarily through the efficiency with which employees are deployed. More specifically, enhanced employee productivity results were observed in both static analyses that assessed the performance of the sample Six Sigma firms relative to their control groups at discrete points in time and dynamic analyses of the Six Sigma firms’ rate of improvement relative to the rate of improvement of their control groups. Benefits in terms of improved asset efficiency were not observed. Finally, there was no evidence that Six Sigma negatively impacts corporate performance.     

Six Sigma: The role of goals in improvement teams

The tenets of goal theory have been well established as a motivation mechanism in the management literature. However, some quality-management advocates, such as W. Edwards Deming, often criticize the use of goals. This research investigates the tension between goals and quality management in the Six Sigma context. We find empirical support that goals can be effective in Six Sigma improvement teams when teams adhere to the Six Sigma tools and method. However, challenging goals are counterproductive when Six Sigma teams do not use the tools and methods rigorously. This research reconciles the differences between quality management and goal theory by showing that the Six Sigma tools and method interact with goals.     

Six Sigma and information systems project management: A revised theoretical model

Previous information systems (IS) research has significantly improved the success rate of IS projects, but the result is still far from satisfying. The effort to advance IS project management theories continues. One notable effort is Ravichandran and Rai (2000). Based on quality management principles, they developed a model (the R&R model) describing a qualityoriented organizational system that leads to software development quality performance. This study analyzed Six Sigma to propose major revisions to the R&R model. Six Sigma is a recent approach to quality management with proven effectiveness. The analysis of Six Sigma suggested that several constructs in the R&R model need to be respecified, leading to the definition of a new quality‐oriented organizational system. More importantly, the revised model posits that the new organizational system leads to IS project success that can be measured by organizational performance improvement. This study contributes to the literature and provides practical guidance to IS project managers.     

六西格玛理论在高职单独招生管理中的应用

本文从介绍六西格玛质量管理基本内容入手,就当前高职招生管理中的一些突出问题,有针对性地提出应用六西格玛质量管理方法加以改进的意见与措施。     

Six Sigma adoption: Operating performance impacts and contextual drivers of success

We assess the operational impacts of Six Sigma program adoptions through an event study methodology, comparing financial data for 200 Six Sigma adopting firms against data for matched firms, which serve as control groups for the analyses. We employ various matching procedures using different combinations of pre-adoption return on assets (ROA), industry, and size as matching criteria. By comparing performance outcomes across a hierarchy of operating metrics, we establish a pattern of Six Sigma adoption effects that provides strong evidence of a positive impact on ROA. Interestingly, these ROA improvements arise mostly from significant reductions in indirect costs; significant improvements in direct costs and asset productivity are not evident. We also find small improvements in sales growth due to Six Sigma adoption. Cross-sectional analyses of the performance results reveal that distinctions in Six Sigma impacts across manufacturing and service firms are negligible. Interestingly, we find that the performance impact of Six Sigma adoption is negatively correlated to the firm's quality system maturity (indicated by prior ISO 9000 certification). Further analyses of manufacturing and service firms reveals that Six Sigma benefits are significantly correlated with intensity in manufacturing, and with financial performance before adoption in services. We discuss the implications of these findings for practice and for future research.     

现代产品的质量改进和六西格玛管理

高度自动化是现代制造系统的主要特征,自动化设备的广泛采用对质量提出了越来越高的要求。这就要求产品的质量不断的改进和提高,而六西格玛(6σ)理论是一套建立在统计学基础上的质量管理系统模式。它的本质是不断减少偏差,持续追求高品质。文中综述了现代产品的质量研究改进和六西格玛管理理论。     

Constructing useful theory: The case of Six Sigma

Organizational practices related to Six Sigma are believed to have resulted in improved organizational outcomes. The academic community, however, continues to lack understanding of the constructs and causal relationships underlying Six Sigma. Hence, discussion of Six Sigma is buffeted by anecdotal experience reported from practice. We evaluate Six Sigma through the lens of literature on theory development to explain why the Six Sigma constructs, assumptions, and causal relationships are inconsistent with theory development principles. Dr. Anilkumar N. Kharkar has retired from Corning Incorporated.     

六西格玛管理——企业竞争制胜的利器

激烈的市场竞争要求企业具备低成本、高质量。六西格玛管理能有效识别并消除变异、提高质量、持续改进,是企业增强竞争优势的有效途径。本文通过分析六西格玛管理模式的内涵,提出当前金融危机环境下实施六西格玛管理的必要性。通过分析我国实施六西格玛的现状,阐述了当前我国企业实施六西格玛的重要现实意义。作为一种有效的质量管理模式,六西格玛不是单纯的技术方法的引用,它代表了先进的质量管理发展方向。此研究将有助于我国企业管理层科学地认识六西格玛,也有助于该方法在我国企业的推广。     

Lessons from Sweden’s first large-scale implementation of Six Sigma in healthcare

The Skaraborg Hospital Group (SkaS) has implemented a variety of quality management initiatives in the last 20 years in accordance with its strategy of excelling at quality development to fulfill the needs and expectations of its patients. One such initiative is Six Sigma, which has contributed to more than 40 completed improvement projects. Using an action research approach, this article describes the lessons that were learned from the first 22 Six Sigma projects, completed between 2006 and 2008 and having a success rate of 75%. We further describe how these insights have contributed to other ongoing quality improvement activities at SkaS. In particular, the paper presents some key points not earlier described in other Six Sigma healthcare applications.     

基于平衡计分卡的六西格玛项目选择指标体系构建

企业如何对六西格玛项目进行选择,选择一个科学的评价体系至关重要。文章借鉴了六西格玛平衡计分卡原理和SWOT企业战略管理分析理论,通过财务、顾客、内部业务流程以及学习和成长四个维度分析,最后经过咨询质量管理专家,对指标进行修正,构建了基于六西格玛平衡计分卡的评价体系,希望能够为六西格玛项目选择提供一个有益的借鉴。     

Increasing perceived work meaningfulness by implementing psychological need-satisfying performance management practices

To further investigate the relationship between human resource practices and organizational performance, research suggests focusing on psychological employee outcomes. In this paper, it is proposed that the positive psychological concept of work meaningfulness constitutes a mediator between human resource practices and performance which is worth investigating. The author argues that performance management practices can potentially lead to an increase in employees' perceived work meaningfulness, if they focus on satisfying the three psychological needs for competence, autonomy, and relatedness. Based on findings from research focusing on performance management trends, goal setting, performance appraisal, performance feedback, and self-determination theory, the paper suggests a new perspective on how to incorporate concepts rooted in the science of positive psychology in performance management practices to contribute to positive workplace outcomes such as well-being and performance.     

港口供应链的精益六西格玛物流模式研究

文章分析了港口供应链物流管理模式现状及存在的问题,介绍了精益六西格玛管理思想的概念及特点,根据精益六西格玛思想对物流管理的影响与作用,提出了应用于港口供应链的精益六西格玛管理模式。     

中国企业六西格玛管理实施模型研究

随着六西格玛管理的迅速推广,不少中国企业通过实施六西格玛取得了显著的效益,当在实施六西格玛管理过程中也存在很多问题。因此,了解六西格玛在中国的实施现状,总结适合中国企业实施六西格玛管理的模式至关重要。文章基于对六西格玛管理关键成功因素的分析,构建了适合中国企业的六西格玛管理实施模型。为中国企业通过实施六西格玛管理建立一套持续改进的管理模式奠定了基础。     

Project management infrastructure: The key to operational performance improvement

Process improvement programs such as Six Sigma, Lean, and Lean Sigma are very important and deserve serious academic research attention. However, definition problems make it difficult to study any specific type of process improvement program. Therefore, this study defines two organizational level program management factors, Strategic Project Selection (SPS) and Project Management Infrastructure (PMI), that are independent of any specific process improvement program. Drawing upon current literature, this study develops and tests theoretical models that relate SPS and PMI to operational performance improvement and to each other. Using empirical data collected from 53 supplier plants of one large high-tech firm, this study finds that at the plant level, SPS mediates the relationship between PMI and operational performance improvement. This insight contributes to both theory development and practice, suggesting that a viable strategy for a process improvement program’s success is to focus on PMI in order to enhance SPS and ultimately improve performance. Not to be reproduced or quoted without written permission from the authors.     

A replication and extension of quality management into the supply chain

As competition moves beyond a single firm into the supply chain, researchers are beginning to explore quality management (QM) in a supply chain context. The literature suggests that supply chain management (SCM) consists of internal practices, which are contained within a firm, and external practices, which cross organizational boundaries integrating a firm with its customers and suppliers. Supplier quality management and customer focus are two QM practices that are also clearly in the domain of SCM. In this study we investigate how these two supply chain management-related quality practices lead to improved performance and examine the practices that precede and mediate those relationships. In doing so, we replicate and extend the relationships among the QM practices and their effects on firm performance suggested in Kaynak [Kaynak, H., 2003. The relationship between total quality management practices and their effects on firm performance. Journal of Operations Management 21, 405–435] using survey data gathered from firms operating in the U.S. The inclusion of customer focus and supplier quality management in the QM model supports the importance of internal and external integration for quality performance. Implications of the results for researchers and practitioners are discussed, and further research implications are suggested.     

基于6sigma的采购质量改进研究

将6sigma的管理方法引入采购质量管理中,运用6sigma定义的DMAIC五个步骤对采购过程的质量进行定义、评估、分析、改进和控制,从而达到提高采购过程质量水平的目的。     

Ten years after: Interference of hospital slack in process performance benefits of quality practices

We investigate the long-term relationship between an organization's quality management practices and process-level performance. Further, we examine whether availability of organizational slack over the study interval interferes with the relationship between quality practices and process performance. Organizational slack consists of the available and accessible resources in an organization; we focus here on unabsorbed slack in the form of financial resources. We investigate the quality practices of U.S. general acute care hospitals, measured by their depth of implementation of practices characterizing a total quality management system, and use them to predict process performance related to four medical conditions. Analysis reveals differing effects that are dependent on hospital slack conditions. In hospitals with high slack, quality practices significantly predict three of four studied process performance measures. In contrast, in hospitals with low slack, quality practices predict only one of the four process performance measures, while other factors outweigh the effects of quality practices. This study lends support to management taking a long-term perspective related to implementation of quality management systems, and highlights the relevance of slack conditions in garnering the benefits of such systems.     

Linking human resource management practices and customer satisfaction on product quality

Although research has addressed relationships between human resource management (HRM) practices and several firm performances, it remains rare for studies to assess the processes that may underlie such relationships. This study aims to investigate the relationships between HRM practices and product quality by hypothesizing a mediating role of organizational commitment. We design a conceptual model and construct hypotheses that are tested using structural equation modeling on data collected from an international sample. The study contributes to the theoretical and empirical development of a model to explain and open the black box between skill-developing HR practices and quality performance.