Lean,Six Sigma and Lean Six Sigma: an analysis based on operations strategy

There is a growing need for operations management models that contribute to the continuous improvement of company processes, among them we highlight lean manufacturing, Six Sigma and, more recently, Lean Six Sigma (LSS). This article aims (1) to identify and analyse the differences and complementarities in the production decision areas for each one of the three models; (2) to identify the competitive priorities that lead to the best performance as a result of policies followed in the decision areas as a result of the adopted model. First, a theoretical conceptual model was developed based on a review of the literature, followed by a exploratory research questions applied to manufacturing companies that use the lean, Six Sigma or LSS manufacturing models in southern Brazil. The main results show that there are differences in the models in relation to the importance of the decision areas and the performance achieved in the competitive priorities. Individually, lean manufacturing, Six Sigma and LSS have varying degrees of importance in the Facilities, Vertical Integration and Production Planning and Control decision areas. The performance dimensions with the best performance are speed, quality, reliability and cost.     

On the evaluation of Six Sigma projects

Most of the research on the success in implementing Six Sigma agrees upon the fact that one of the key success factors is the selection of profitable projects. This seems to be especially important for high‐risk, large‐scope and long‐term projects, as is mostly the case in the design for Six Sigma projects. The purpose of this paper is to outline Six Sigma project characteristics and to present a new model for evaluating Six Sigma projects. To design a Six Sigma project evaluation model, we utilized mathematical optimization modeling techniques and real options theory. The model allows for the quantification of not only the project's value prior to its start but also its progress and the consideration of possible decisions based on this progress. Copyright © 2009 John Wiley & Sons, Ltd.     

A framework for the integration of Green and Lean Six Sigma for superior sustainability performance

Evidence suggests that Lean, Six Sigma and Green approaches make a positive contribution to the economic, social and environmental (i.e. sustainability) performance of organisations. However, evidence also suggests that organisations have found their integration and implementation challenging. The purpose of this research is therefore to present a framework that methodically guides companies through a five stages and sixteen steps process to effectively integrate and implement the Green, Lean and Six Sigma approaches to improve their sustainability performance. To achieve this, a critical review of the existing literature in the subject area was conducted to build a research gap, and subsequently develop the methodological framework proposed. The paper presents the results from the application of the proposed framework in four organisations with different sizes and operating in a diverse range of industries. The results showed that the integration of Lean Six Sigma and Green helped the organisations to averagely reduce their resources consumption from 20 to 40% and minimise the cost of energy and mass streams by 7–12%. The application of the framework should be gradual, the companies should assess their weaknesses and strengths, set priorities, and identify goals for successful implementation. This paper is one of the very first researches that presents a framework to integrate Green and Lean Six Sigma at a factory level, and hence offers the potential to be expanded to multiple factories or even supply chains.     

Using the theory of constraints to guide the implementation of quality improvement projects in manufacturing operations

Several studies have shown that more than 70% of all medium to large size companies (sales exceeding $19 million) have some form of quality improvement program in place. Based on independent studies by Arthur D. Little, Ernst & Young, and others, researchers have concluded that only about one-fifth of all QI programs achieve tangible results. One explanation for the disappointing results is that many quality improvement efforts are not results-oriented. The purpose of this paper is to demonstrate the value of using the theory of constraints for achieving a results-oriented quality improvement program.     

Sustainability of process improvements: an application of the experiential learning model (ELM)

Despite the pervasiveness of process improvement (Lean or Six Sigma) programmes, there is a rising concern regarding the sustainability of these programmes. Several studies point out that initial operational efficiency gains as a result of these programmes simply disappear over time. Using process improvement implementation experiences in an aircraft manufacturing and distribution operation, we studied long-term sustainability of process improvement events. We found that process owners of successful improvement events applied experiential learning model (ELM). The ELM is a cycle of – (1) concrete experience, (2) reflective observations, and (3) abstract conceptualizations, and (4) active experimentation. This study finds that when the ELM cycle is repeated many times over an extended period to continuously improve, and documented using A3 reports, that the improvement is sustained.     

The Role of Statistical Design of Experiments in Six Sigma: Perspectives of a Practitioner

Six Sigma has now been well recognized as an effective means of attaining excellence in the quality of products and services. It entails the use of statistical thinking as well as management and operational tools to bring about fundamental improvements. This article explains, in a nonmathematical language, the rationale and mechanics of design of experiments as seen in its deployment in Six Sigma. It also outlines the way in which the design of experiments has been utilized in the past for quality improvement, culminating in its important role in Six Sigma. An appreciation of the changing scope of experimental design applications over the years and in the future would provide useful perspectives on the significance of Six Sigma in an organization's quest for quality excellence.     

工业产品造型中布尔运算的运用

布尔运算是造型的基本算法之一,它有较高的通用性和低效率的特点.文章分析了布尔运算低效及呆板的原因,并通过解析造型实例,提出了减少操作修改和提高布尔运算效率的组织策略和运用技巧,这在生产企业的设计与制造中还是有可观的效益.     

IT investments and business performance improvement: the mediating role of lean manufacturing implementation

The main purpose of this study is to examine whether the application of current information technology (IT) and different principles of lean manufacturing (LM) are interdependent and complimentary or they are mutually exclusive. This study draws on the so-called IT-enabled organisational capabilities perspective to study the relationships between IT, LM and business performance improvement. Using a questionnaire-based survey, the data come from 231 leading Iranian and Malaysian auto-part manufacturers. The findings suggest that LM and IT are mutually interdependent and value of IT investments can be effectively transformed into business performance improvement for auto-part manufacturers through the higher levels of lean manufacturing system (LMS) implementation. Advanced manufacturing technology (AMT) competency is a valuable intermediate capability which links IT investments into LMS implementation. It was found that IT investment is one of the minimum requirements of LMS implementation for surveyed business, and the value of IT investment is truly transformed to LMS implementation when IT investments offer competent administrative AMTs to effectively manage all production processes. Findings also recommend that managers should avoid isolating the performance metrics only on areas such as net financial measures, while assessing the business value of IT and LM.     

Six Sigma企业与品质管理系统在制膜工业上的应用

六西格玛作为一种有效的企业和品质管理系统,已被许多美国大公司采用．将六西格玛用于制膜工业,可以使膜产品具有更强的市场竞争力．文章通过一些实例,介绍了六西格玛在科研和制膜方面的应用．     

Applying performance measures to support decision-making in supply chain operations: a case of beverage industry

Performance measurement systems (PMS) have commonly been applied to evaluate and reward performances at managerial levels, especially in the context of supply chain management. However, evidence suggests that the effective use of PMS can also positively influence the behaviour and improve performance at an operational level. The motivation is to accomplish organisational goals, namely to increase supply chain flexibility by responding to evermore-varying customer demands in a timely manner. The purpose of the study described in this paper was to develop a conceptual framework that adopts performance measures for ex-ante decision-making at an operational level within the supply chain. To guide the research, five questions were asked and subsequently key gaps have been identified. In an attempt to fill the gaps, a case study at a major global brand beverage company has been carried out, and as a result, a conceptual framework of the PMS has been developed. Overall, the research offers a foundation of the applicability and impact of PMS in the supply chain and provides a framework that attends to some of the potential uses of PMS that so far have not been practically applied. The outcomes from the testing indicate that the initial gaps identified in the literature have been addressed and that the framework is judicious with scope for practical applicability. The framework is deemed worthy of further testing in different operational contexts of the supply chain.     

Integration of PCA and DEA for identifying and improving the impact of Six Sigma implementation on job characteristics in an automotive industry

This study presents an integrated approach, based on data envelopment analysis (DEA) and principal component analysis (PCA) methods, to evaluate the influence of Six Sigma deployment on key job characteristics in an automotive industry. The job characteristics are defined as satisfaction, stress, and security. A standard questionnaire is designed and distributed among the employees at the company's production site, who were affected by the implementation of Six Sigma. DEA and PCA methods are applied to measure the performance of the sub-groups of employees in the company. Consequently, the most efficient and inefficient sub-groups are determined. According to the findings of this investigation, it was perceived that the implementation of Six Sigma has had the greatest impact on job satisfaction. Additionally, a design of experiment was carried out to recognize the most effective job factor, which was identified to be the overall working conditions for the related case study. This is the first study that integrates DEA and PCA toward identifying and optimizing job characteristics in terms of Six Sigma implementation. The approach, employed in this study, can be easily used in the other manufacturing systems, in order to assist them to identify and improve their key job characteristics.     

The impact of lean methods and tools on the operational performance of manufacturing organisations

Evidence suggests that lean methods and tools have helped manufacturing organisations to improve their operations and processes. However, the real effect of these methods and tools on contemporary measures of operational performance, i.e. cost, speed, dependability, quality and flexibility, is still unclear. This paper investigates the impact of five essential lean methods, i.e. JIT, autonomation, kaizen, total productive maintenance (TPM) and value stream mapping (VSM), on these measures. A linear regression analysis modelled the correlation and impact of these lean practices on the operational performance of 140 manufacturing organisations around the world. In addition, structural equation modelling (SME) was used to cross verify the findings of the regression and correlation analyses. The results indicate that JIT and automation have the strongest significance on operational performance while kaizen, TPM and VSM seem to have a lesser, or even negative, effect on it. This paper provides further evidence regarding the effects that lean practices have on the performance of organisations and thus the research offers companies, and their managers, a better understanding of the relationship between the lean strategy and the performance of their operations.     

A framework for assessing the use of lean production practices in manufacturing cells

This study introduces a framework for assessing the use of lean production (LP) practices in manufacturing cells (MCs). The development of the framework included four stages: (a) defining LP practices applicable to MC, based on criteria such as the inclusion of practices that workers could observe, interact with and use on a daily basis; (b) defining attributes for each practice, emphasising the dimensions which were typical of their implementation in LP environments; (c) defining a set of evidence and sources of evidence for assessing the existence of each attribute–the sources of evidence included direct observations, analysis of documents, interviews and a feedback meeting to validate the assessment results with company representatives; (d) drawing up a model of the relationships among the LP practices, based on a survey with LP experts. This model supports the identification of improvement opportunities in MC performance based on the analysis of their interfaces. A case study of an MC from an automobile parts supplier is presented to illustrate the application of the framework.     

The fit of planning methods for the part manufacturing industry,a case study

This paper investigates the specific planning environment of an automotive part manufacturer and characterizes this environment based on variables regarding the product,its demand and the manufacturing process.The fit of different planning methods,namely material requirements planning,reorder point,cyclic planning,kanban,and heijunka to this specific planning environment is analyzed and evaluated by exploratory research.The results show that different product characteristics make it hard to apply a single planning method.None of the investigated methods show the ability to cover the complex requirements of a combined planning environment of two partly divergent product types with a deep value chain.     

Requirements in performance measurement systems of construction projects from the lean production perspective

Performance measurement (PM) generates useful data for process control, facilitates communication between different sectors, and helps to align efforts on the most important aspects of the business. Thus, PM plays a key role in the management of projects and organizations. PM is also important in the implementation of lean production principles and methods, such as reducing the share of nonvalue-adding activities, increasing process transparency, building continuous improvement into the process, and benchmarking. Moreover, the adoption of the lean production philosophy requires changes in PM. Despite its importance, limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects. In addition, studies on how lean companies (or projects) use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited. This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems. Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems. The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.     

低温微创手术高真空绝热治疗探杆研制

介绍低温微创手术高真空绝热治疗探杆的结构和制作方法,对制作过程中小直径簿壁不锈钢套管焊接;微小间隙抽真空以及真空检漏等应注意的问题进行探讨.临床应用表明,探杆采用真空度1×10-4Pa的高真空绝热能够实现良好的绝热性能;可以满足低温微创手术对探杆绝热的要求.     

美国典型军工企业六西格玛设计应用及其启示

六西格玛设计(Design for Six Sigma,DFSS)是近年来国外军工企业广泛应用的质量工程方法。从提升装备设计质量的角度出发,综述了美国通用电气、霍尼韦尔及雷神等典型军工企业DFSS应用情况及其展开路径,并分析了DFSS发展路线。结合我国装备研制的实际情况,总结了我国装备研制中DFSS应用的几点启示。     

The role of cue utilisation and adaptive interface design in the management of skilled performance in operations control

The operational control of complex systems such as power control and air traffic control is increasingly relegated to advanced technology devices with the expectation that operations controllers will maintain oversight of system and intervene where appropriate. Moreover, the centralisation of operations control has resulted in the oversight of systems remotely, typically through a human–machine interface. This article discusses the principles that underlie the design of interfaces for remote systems, drawing on theories of skill acquisition to address the needs of less experienced operators who are increasingly being engaged as operations controllers. Specifically, adaptive interfaces are advocated that are designed to facilitate the progression to expertise. Using cue utilisation as an underlying theoretical perspective, interfaces can be designed to extract and emphasise the relationship between features and events that eventually form the basis of the cues employed by expert practitioners.     

Modeling the effects of digital transformation in Indian manufacturing industry

Digital transformation has become the new norm and is perceived as an important component to transform the firms’ businesses. It has revolutionized the way in which firms conduct their businesses. However, the literature has not widely examined the holistic impact of key antecedents of digital transformation on manufacturing firm performance. The study aims to identify the antecedents of digital transformation and demonstrates the mediating role of digital transformation on firm performance. Using PLS-SEM modeling reveals that there is a considerable impact of competitive pressure, organizational mindfulness, IT readiness, and strategic alignment on digital transformation. Also, digital transformation mediates the effects of the antecedents on the performance of the firm. The practitioners and firms would be motivated to seize the digital transformation advantages as an opportunity to improve firm performance.