Six Sigma quality: a structured review and implications for future research

Application of Six Sigma methodology to enhance the productivity and performance of a hotel in the UAE

Purpose

The hotel industry is one of the primary sectors contributing to every country's economy by promoting and reinforcing tourism. The pandemic situation across the globe is forcing the hospitality industry to adopt a suitable operational excellence (OPEX) methodology and its associated tools to deliver quality service at an affordable cost. However, there is limited evidence of applying one of the prominent OPEX methodologies, such as Six Sigma (SS), to enhance the hospitality industry's productivity and performance. Thus, the purpose of the study is to explore the application of the SS methodology to reduce the cycle time of a pantry workstation in a United Arab Emirates (UAE) hotel sector.

Design/methodology/approach

The research adopted a case study approach using DMAIC (define-measure-analyse-improve-control) phases to improve the performance of the minibar updating process attached to the hotel rooms. In addition, the study effectively used several tools, including normality tests, control charts, capability analysis, cause and effect diagram, failure mode effects analysis (FMEA), value stream mapping (VSM) and GEMBA, to validate the root causes and draw robust inferences.

Findings

The average cycle time and standard deviation of the pantry process were drastically reduced. Further, the analysis showed that the process capability index was substantially improved. Consequently, a notable improvement in the process performance was witnessed, which has resulted in a profit of $50,000 per annum in the hotel.

Practical implications

The article provides a structured and disciplined approach of SS in a hotel which can be used as a benchmarking document by the academicians, practitioners and policymakers for OPEX within the hospitality industry. Further, it paves the way to develop a road map for applying SS in the hospitality sector.

Originality/value

As per the authors' knowledge, to date, no case study has been reported in top tier refereed journals regarding the application of SS in the hotel sector. Thus, the current case study bridges this gap and reiterates that SS can be effectively used with meticulous planning and deployment in the hospitality industry.

Performance and service quality enhancement in a healthcare setting through lean six sigma strategy

Purpose

The article intended to excavate the Lean Six Sigma (LSS) deployment challenges, Critical Success Factors (CSF), tools and techniques, and managerial implications in an Indian healthcare setting.

Design/methodology/approach

The article illustrates a case study established using Action Research (AR) approach. Further, the case study is based on the Define, Measure, Analyze, Improve, Control (DMAIC) phases of LSS. The performance and service quality of the Endodontics department of a dental college attached to a hospital is enhanced and sustained through the LSS strategy.

Findings

The processing time of Root Canal treatment is reduced by determining the root causes for delay and implementing sustainable solutions. The structured deployment of the LSS strategy helped the Endodontics department to reduce the processing time from an average of 116 min–84 min. Thus, the process's sigma level is enhanced from 0.06 to 4.17 and assisted in sustaining the results.

Research limitations/implications

The case study's findings are based on the single AR carried out at an Endodontics department of a dental college hospital based on LSS strategies. Even though this study's results cannot be generalized, the deliverables of the case study can be used to develop the LSS roadmap for the dental colleges to enhance the service quality and safety of the patients.

Originality/value

The article provides step-by-step details for implementing LSS in dental college hospitals with critical analysis based on robust statistical tools and techniques. The case study provides evidence of the adoption of LSS in medical college education and provides the confidence to adopt the same through novice users. The study's findings may persuade the policymakers to add LSS in the medical education curriculum to reinforce safety and reduce errors in the healthcare system.

Impact of perceived importance of cultural readiness factors on perceived importance of Lean Six Sigma success factors for manufacturers

Purpose

This study aims at investigating the impact of the perceived importance of critical cultural readiness factors (CRFs) is on perceived importance of Lean Six Sigma (LSS) technical critical success factors (CSFs) in UK manufacturing sector.

Design/methodology/approach

A survey questionnaire through a multiple embedded case study was conducted. The study involves surveying people in the manufacturing firms followed by non-parametric Kruskal–Wallis test to study the relationships.

Findings

It was found that the people's perception towards impact of CRFs on technical CSFs of LSS projects is different depending upon each CRF, demographic factors and technical CSFs. This means that particular CRFs need to be prioritised to address LSS technical CSFs.

Research limitations/implications

The study fills the research gap in investigating the perception of people towards inter-relationship of cultural or soft CSFs of LSS and technical or hard CSFs of LSS in manufacturing firms. Nevertheless, the authors suggest further multi-case study analysis covering different manufacturing fields as future studies.

Practical implications

The study is crucial for managers financially to be ready to invest on a successful LSS project and it helps them to diagnose the cultural causes of failure in a more timely way and effectively.

Originality/value

This is a preliminary study focussing on analysing inter-relationship between perceived importance of soft readiness factors and perceived importance of implementing success factors as a missing jigsaw in the current literature.

A Realist Inquiry to Identify the Contribution of Lean Six Sigma to Person-Centred Care and Cultures

A lack of fidelity to Lean Six Sigma's (LSS) philosophical roots can create division between person-centred approaches to transforming care experiences and services, and system wide quality improvement methods focused solely on efficiency and clinical outcomes. There is little research into, and a poor understanding of, the mechanisms and processes through which LSS education influences healthcare staffs' person-centred practice. This realist inquiry asks 'whether, to what extent and in what ways, LSS in healthcare contributes to person-centred care and cultures'. Realist review identified three potential Context, Mechanism, Outcome configurations (CMOcs) explaining how LSS influenced practice, relating to staff, patients, and organisational influences. Realist evaluation was used to explore the CMOc relating to staff, showing how they interacted with a LSS education Programme (the intervention) with CMOc adjudication by the research team and study participants to determine whether, to what extent, and in what ways it influenced person-centred cultures. Three more focused CMOcs emerged from the adjudication of the CMOc relating to staff, and these were aligned to previously identified synergies and divergences between participants' LSS practice and person-centred cultures. This enabled us to understand the contribution of LSS to person-centred care and cultures that contribute to the evidence base on the study of quality improvement beyond intervention effectiveness alone.

Responsible Innovation in SMEs: A Systematic Literature Review for a Conceptual Model

Responsible innovation has always been an important issue in discourses addressing the major challenges faced by humankind in terms of natural resource degradation, climate change, economic progress and societal well-being. However, its integration into industry is still in its infancy, and even more so when it comes to small and medium-sized enterprises (SMEs). The aim of this research is to use a systematic literature review to develop a conceptual model for responsible innovation and its relationship with SME performance, in connection with sustainable innovation and corporate social responsibility practices. A bibliometric analysis of 102 articles collected between 2000 and April 2020 from the Web of Science database was used, in addition to the systematic literature review using the Gephi and NVivo software. The study presents an overview of the articles, authors, and most influential journals and research clusters identified, and provides a solid conceptual framework to be applied in this field and in the context of SMEs.

Six Sigma quality evaluation of life test data based on Weibull distribution

Purpose

While Six Sigma metrics have been studied by researchers in detail for normal distribution-based data, in this paper, we have attempted to study the Six Sigma metrics for two-parameter Weibull distribution that is useful in many life test data analyses.

Design/methodology/approach

In the theory of Six Sigma, most of the processes are assumed normal and Six Sigma metrics are determined for such a process of interest. In reliability studies non-normal distributions are more appropriate for life tests. In this paper, a theoretical procedure is developed for determining Six Sigma metrics when the underlying process follows two-parameter Weibull distribution. Numerical evaluations are also considered to study the proposed method.

Findings

In this paper, by matching the probabilities under different normal process-based sigma quality levels (SQLs), we first determined the Six Sigma specification limits (Lower and Upper Six Sigma Limits- LSSL and USSL) for the two-parameter Weibull distribution by setting different values for the shape parameter and the scaling parameter. Then, the lower SQL (LSQL) and upper SQL (USQL) values are obtained for the Weibull distribution with centered and shifted cases. We presented numerical results for Six Sigma metrics of Weibull distribution with different parameter settings. We also simulated a set of 1,000 values from this Weibull distribution for both centered and shifted cases to evaluate the Six Sigma performance metrics. It is found that the SQLs under two-parameter Weibull distribution are slightly lesser than those when the process is assumed normal.

Originality/value

The theoretical approach proposed for determining Six Sigma metrics for Weibull distribution is new to the Six Sigma Quality practitioners who commonly deal with normal process or normal approximation to non-normal processes. The procedure developed here is, in fact, used to first determine LSSL and USSL followed by which LSQL and USQL are obtained. This in turn has helped to compute the Six Sigma metrics such as defects per million opportunities (DPMOs) and the parts that are extremely good per million opportunities (EGPMOs) under two-parameter Weibull distribution for lower-the-better (LTB) and higher-the-better (HTB) quality characteristics. We believe that this approach is quite new to the practitioners, and it is not only useful to the practitioners but will also serve to motivate the researchers to do more work in this field of research.

Lean Six Sigma competitiveness for micro, small and medium enterprises (MSME): an action research in the Indian context

Purpose

The aim of the article is to ascertain the challenges, lessons learned and managerial implications in the deployment of Lean Six Sigma (LSS) competitiveness to micro, small and medium Enterprises (MSME) in India and to establish doctrines to strengthen the initiatives of the government.

Design/methodology/approach

The research adopts the Action Research methodology to develop a case study, which is carried out in the printing industry in a Tier III city using the LSS DMAIC (Define-Measure-Analyze-Improve-Control) approach. It utilizes LSS tools to deploy the strategy and to unearth the challenges and success factors in improving the printing process of a specific batch of a product.

Findings

The root cause for the critical to quality (CTQ) characteristic, turn-around-time (TAT) is determined and the solutions are deployed through the scientifically proven data-based approach. As a result of this study, the TAT reduced from an average of 1541.2–1303.36 min, which in turn, improved the sigma level from 0.55 to 2.96, a noteworthy triumph for this MSME. The company realizes an annual savings of USD 12,000 per year due to the success of this project. Top Management Leadership, Data-Based Validation, Technical Know-how and Industrial Engineering Knowledge Base are identified as critical success factors (CSFs), while profitability and on-time delivery are the key performance indicators (KPIs) for the MSME. Eventually, the lessons learned and implications indicate that LSS competitiveness can be treated as quality management standards (QMS) and quality tools and techniques (QTT) to ensure competitive advantage, sustainable green practices and growth.

Research limitations/implications

Even though the findings and recommendations of this research are based on a single case study, it is worth noting that the case study is executed in a Tier III city along with novice users of LSS tools and techniques. This indicates the applicability of LSS in MSME and thus, the modality adopted can be further refined to suit the socio-cultural aspects of India.

Originality/value

This article illustrates the deployment of LSS from the perspective of novice users, to assist MSME and policymakers to reinforce competitiveness through LSS. Moreover, the government can initiate a scheme in line with LSS competitiveness to complement the existing schemes based on the findings of the case study.

Six Sigma Project Procurement application in public procurement

Purpose

Project management tools and techniques have been widely adopted in the construction industry; however, its combination with Six Sigma and application in construction procurement has not been widely researched. This paper explores the use of Six Sigma Project Procurement (SSPP) and its potential applications in public sector construction procurement.

Design/methodology/approach

The role of Six Sigma and project management in construction is critically evaluated using three case studies to demonstrate their application in public procurement.

Findings

The use of SSPP by public sector organisations creates efficient and effective construction procurement processes by addressing delays. The proposed timelines for competitive tendering in the Ghanaian Public Procurement Manual are not realistic.

Research limitations/implications

This paper contributes to and broadens the limited body of evidence and knowledge of applying SSPP to public procurement processes and identifies areas for further research.

Practical implications

Project management will continue to expand in the global construction industry. However, what will eventually determine if SSPP is embraced by public sector construction depends on the leadership and success of its execution. The application of SSPP to public construction procurement will address delays and lead to significant time reduction of the process. This will eliminate the major issue (delay) accounting for deficiencies in the process.

Originality/value

The paper yields immense value to construction project management researchers and practitioners, especially in the public sector. It recommends the inclusion of Six Sigma to promote focus on actual instead of perceived problems and advocates for decisions-making based on facts which will ensure continuous improvement.

The relationship between quality and governance mechanisms

Purpose

Recent literature has highlighted the importance of quality and governance in supply networks. Usually, the relationships between the actors are complex, comprising both formal and informal interactions. Despite recent advances in quality and governance in supply networks, extant literature highlights the lack of quality in healthcare supply-chain networks in relation to governance mechanisms. This paper aims to investigate the role of governance mechanisms and their influence on the quality of healthcare supply networks, and assumes that governance instruments can support quality performance.

Design/methodology/approach

A multiple-case research approach was employed. Six organisations in the Brazilian healthcare sector were analysed (four operate only with renal replacement therapy, one is a material supplier, and one operates with renal replacement therapy and collective procurement).

Findings

Findings showed that there is no formalised supply network structure in these organisations. A possible consequence of this is that the supply-network governance is dominated by informal relationships. In the quality dimension, managers' awareness is limited, but there are mechanisms in place to control the quality of the materials.

Practical implications

Healthcare managers can actively invest in the social aspects of the relationship between buyer and supplier, such as trust and commitment, thus increasing responsiveness in patient care. However, this informal procedure can lead to problems with tracking and reliability, ultimately leading to quality problems. Therefore, it is recommended that formal and informal governance instruments be used jointly to improve service quality.

Originality/value

This study suggests that the integration of formal and informal mechanisms of governance can improve the quality of supply networks. Additionally, if the administrative process is purely formal, network relationships and their efficiency will be impaired.

Rigor and reproducibility in polymer nanoparticle synthesis and characterization

Standardized process improvement methods and tools were used to enhance the rigor and reproducibility of diblock copolymer nanoparticle (NP) synthesis and characterization. Models linking design parameters with NP characteristics boosted process control for NP synthesis, which may improve translation and commercialization of NP research.

Six Sigma metrics based on lognormal distribution for life tests

Purpose

The purpose of this paper is to propose an approach for studying the Six Sigma metrics when the underlying distribution is lognormal.

Design/methodology/approach

The Six Sigma metrics are commonly available for normal processes that are run in the long run. However, there are situations in reliability studies where non-normal distributions are more appropriate for life tests. In this paper, Six Sigma metrics are obtained for lognormal distribution.

Findings

In this paper, unlike the normal process, for lognormal distribution, there are unequal tail probabilities. Hence, the sigma levels are not the same for left-tail and right-tail defects per million opportunities (DPMO). Also, in life tests, while left-tail probability is related to DPMO, the right tail is considered as extremely good PMO. This aspect is introduced and based on which the sigma levels are determined for different parameter settings and left- and right-tail probability combinations. Examples are given to illustrate the proposed approach.

Originality/value

Though Six Sigma metrics have been developed based on a normality assumption, there have been no studies for determining the Six Sigma metrics for non-normal processes, particularly for life test distributions in reliability studies. The Six Sigma metrics developed here for lognormal distribution is new to the practitioners, and this will motivate the researchers to do more work in this field of research.

Lean Six Sigma for the healthcare sector: a multiple case study analysis from the Indian context

Purpose

The purpose of this paper is to explore the voice of the customer, key performance indicators, critical to quality characteristics, critical success factors, and commonly used tools and techniques for deploying the Lean Six Sigma (LSS) strategy in Indian private hospitals, with special attention to the medical records.

Design/methodology/approach

The study utilizes the action research methodology to obtain a greater understanding of the use of LSS in the Indian healthcare sector. Multiple case studies were designed and successfully deployed to understand and ascertain challenges in LSS implementation. Five case studies were carried out in the Medical Records Departments (MRD) of four private hospitals in India.

Findings

Patients perceive that waiting in queue harms their health, which can be rectified by addressing the cycle time of the system. The research also found that effective leadership, availability of data, involvement of cross-functional team and effective communication are critical to the success of LSS projects. In addition, control charts, cause and effect diagram, 5S, gemba, two-sample t-test, standardization, waste analysis and value stream mapping are some of the common tools used to improve healthcare systems.

Research limitations/implications

The research was restricted to studying the impact of LSS on the workflow and resource consumption of the MRD in Indian allopathic hospitals only. The validity of the results can be improved by including more hospitals and more case studies from the healthcare sector in different countries.

Originality/value

The findings will enable researchers, academicians and practitioners to incorporate the results of the study in LSS implementation within the healthcare system to increase the likelihood of successful deployment. This will provide greater stimulus across other departments in the hospital sector for wider and broader application of LSS for creating and sustaining process improvements.

A systematic review of Lean in healthcare: a global prospective

Purpose

Fostered by a rapid spread beyond the manufacturing sector, Lean philosophy for continuous improvement has been widely used in service organizations, primarily in the healthcare sector. However, there is a limited research on the motivating factors, challenges and benefits of implementing Lean in healthcare. Taking this as a valuable opportunity, the purpose of this paper is to present the key motivating factors, limitations or challenges of Lean deployment, benefits of Lean in healthcare and key gaps in the literature as an agenda for future research.

Design/methodology/approach

The authors used the secondary data from the literature (peer-reviewed journal articles) published between 2000 and 2016 to understand the state of the art. The systematic review identified 101 articles across 88 journals recognized by the Association of Business Schools ranking guide 2015.

Findings

The systematic review helped the authors to identify the evolution, current trends, research gaps and an agenda for future research for Lean in healthcare. A bouquet of motivating factors, challenges/limitations and benefits of Lean in healthcare are presented.

Practical implications

The implications of this work include directions for managers and healthcare professionals in healthcare organizations to embark on a focused Lean journey aligned with the strategic objectives. This work could serve as a valuable resource to both practitioners and researchers for learning, investigating and rightly adapting the Lean in the healthcare sector.

Originality/value

This study is perhaps one of the comprehensive systematic literature reviews covering an important agenda of Lean in Healthcare. All the text, figures and tables featured here are original work carried by five authors in collaboration (from three countries, namely, India, the USA and the UK).

V, Antony J. Assessment of Lean Six Sigma Readiness (LESIRE) for manufacturing industries using fuzzy logic

Purpose

Many organizations have reported significant benefits after the implementation of Lean Six Sigma (LSS). Embracing LSS requires asking some important questions: How Lean Six Sigma Readiness (LESIRE) can be measured? How can an organization identify the barriers for LESIRE? Answers to these questions are critical to both academicians and practitioners. The paper aims to discuss this issue.

Design/methodology/approach

This study illustrates the development process of a Lean Six Sigma Readiness (LESIRE) evaluation model to assess an organization’s readiness for LSS deployment using the fuzzy approach. The model was developed from 4 enablers, 16 criteria and 46 attributes of LSS, identified through a literature review.

Findings

To demonstrate the efficiency of the model, this study testing the LESIRE evaluation model in three Indian SMEs. Using experts’ ratings and weight, the researchers calculated the Fuzzy Lean Six Sigma index (FLSS) which indicates the LESIRE level of an organization and the Fuzzy Performance Importance Index (FPII) that helps to identify the barriers for LESIRE.

Research limitations/implications

The main limitations of this study are that it did not consider the failure factors of LSS for model development and the LESIRE was only tested in manufacturing industries. Thus, future researchers could focus on developing a model with failure factors. The results obtained from the SMEs show that LESIRE is capable of assessing LESIRE in an industrial scenario and helps practitioners to measure LESIRE for the future decision making process.

Practical implications

The LESIRE model is easy to understand and use without much computation complexity. This simplicity makes the LESIRE evaluation model unique from other LSS models. Further, LESIRE was tested in three different SMEs, and it aided them to identify and improve their weak areas, thereby readying them for LSS deployment.

Originality/value

The main contribution of this study it proposes a LESIRE model that evaluates the organization for FLSS and FPII for LESIRE, which is essential for the organization embarking on an LSS journey. Further, it improves the readiness of the organization that is already practicing LSS.

Six sigma for gamma-distributed processes: a case study in oil and gas

Purpose

The purpose of this paper is to study the relationship between reported sigma levels and actual failure rates (FRs) of gamma-distributed processes. The added complexity of the non-normality behavior of the gamma distribution is analyzed for the case of the cycle time (CT) of a real procurement process from the oil and gas industry. Then, recommendations and guidelines for the application of Six Sigma methodology for the case study are proposed.

Design/methodology/approach

Sensitivity analysis is conducted to study the relationship between gamma distribution parameters and FRs considering different quality levels. Then, adjustments for implementing Six Sigma programs for gamma processes are proposed. These adjustments consist of first determining the appropriate probability distribution, the standard CT and the due date, followed by setting performance zones and improvement strategies on target gamma parameters that yield the minimal FR.

Findings

For gamma-distributed processes, simply reporting the sigma level is not sufficient to capture the main characteristics of the process. These characteristics include process FR, mean setting, shape, spread and amount of variation reduction (i.e. improvement effort) required. That is why caution must be exercised when dealing with one-sided non-normal quality characteristics such as CT.

Originality/value

To the authors’ knowledge, this is the first time that the Six Sigma performance has been evaluated for gamma processes to analyze the link between Six Sigma FRs and gamma distribution parameters leading to the development of a modified Six Sigma methodology for non-normal processes.

Visual management for a dynamic strategic change

Purpose

Strategic changes in an organization will face challenges not only related to the changes as such but also with regard to how the vision of the future is interpreted and understood by the organization. Visual management is a field of research that could contribute to change management research as a means to facilitate management of the dynamics in a change process and to facilitate the process of communication. The purpose of this paper is to problematize episodic change processes with regard to communication and to contribute with a proposed model on how to facilitate dynamic strategic change management using visual management.

Design/methodology/approach

The paper uses an interdisciplinary approach by linking change management literature to visual communication to be used for visual management.

Findings

A proposed model presents how a dynamic episodic change process can be managed in terms of visual management, potential pitfalls to avoid, and what ambidextrous capabilities are needed throughout the complete episodic change.

Research limitations/implications

The proposed model is still yet theoretical, based on a literature review of dynamic change management and visual communication. Future research will validate the model in practice to confirm its robustness.

Practical implications

An implementation of visual management in Kotter’s (1995) eight steps on how to strategically manage change in combination with theories on ambidexterity and episodic change is suggested.

Originality/value

The paper contributes to how visual management can support change management by combining visual communication and change management.

Role of internal and external organizational factors in TQM implementation

Purpose

The purpose of this paper is to provide a conceptual framework for the development of total quality management (TQM) model for service organizations considering both internal and external environmental factors.

Design/methodology/approach

Through an extensive literature search, it is found that despite a large body of knowledge on TQM, there is hardly any research undertaken on the model of service quality including all external and internal factors that can affect the impact of soft and hard TQM factors on organizations performance. So, a systematic literature review has been conducted to extract the relevant journal articles for the study purpose.

Findings

The conceptual model fills this yawning gap and presents a framework of integrated relationships based on several constituent models. These are soft TQM factors, hard TQM factors and organizational performance. Moreover, quality improvement, market benefits, R&D performance and quality performance are used as mediators while industry rivalry and entry barriers are used as moderators between soft and hard TQM and organizational performance. The seven propositions, derived from these elements, highlight the dynamic relationship between above mentioned constructs.

Research limitations/implications

One major limitation is the testing of this model. It has not been tested in any environment or organization to assess its validity. Future research can be done to test the developed hypotheses. Besides three journals, other journals can also be focused in future to get detailed insight into different factors. Impact of IT on organizational processes toward TQM can also be studied in future. More rigorous statistical tests can also be applied to generate more findings with an extension of review time period and selection of more journals.

Practical implications

The model developed in this study can be applied in any service organization with slight modifications to enhance the service quality of organizations by integrating both internal and external aspects for quality improvement. By adopting this framework, organizations can increase their production quality.

Originality/value

This proposed framework will help organizations to effectively implement TQM in their organizations considering internal and external organizational factors.

Personality characteristics and Six Sigma: a review

Purpose

From two bodies of literature, the purpose of this paper is to generate theory for an updated conceptual model of drivers of Six Sigma project success by integrating extant psychology theory and empirical general team project results with a history of eight recent Six Sigma projects and extant Six Sigma literature. The new theory emphasizes the need for project leads to process information simultaneously, as well as develop prioritization abilities. Also, the new theory reverses the relations of three existing theories from general team composition theory. The new theory suggests that Six Sigma belt trainers should focus more on soft skill development.

Design/methodology/approach

A literature review of the two bodies of literature previously mentioned.

Findings

Eight new propositions related to the success of Six Sigma projects are developed. Further, two new constructs, “project leader simultaneity of thought” and “prioritization ability” are suggested for further investigation.

Originality/value

The authors suggest a few practical implications: first a greater emphasis on soft skill training would be beneficial in Six Sigma belt training. A second new point of emphasis in belt training is developing greater internal locus of control in belt candidates. Third, the authors suggest that during the team member selection process a diversity of backgrounds would be beneficial to Six Sigma project success.

Deploying Six Sigma practices to General Electric subsidiaries in a developing economy

Purpose

The purpose of this paper is to investigate Six Sigma implementation in the subsidiaries of General Electric (GE) located in Brazil and to explore the role of the quality culture of headquarters in overcoming common obstacles to Six Sigma implementation reported by other studies.

Design/methodology/approach

An exploratory survey was the basis for gathering data for this study. A structured questionnaire was developed covering issues related to Six Sigma implementation, such as experienced benefits, main outcomes, and metrics adopted by companies. Data from eight GE subsidiaries were qualitatively analyzed. The findings were discussed in the light of other studies conducted in Brazil as well as in other developing countries in the context of the role of existing quality culture in overcoming barriers to Six Sigma implementation.

Findings

The findings revealed that Six Sigma at GE subsidiaries achieved better results in comparison with the results obtained by other Brazilian companies reported in the literature. GE quality culture aspects such as top management commitment, high investment in training, recognition schemes, and development of a well-planned infrastructure were identified as valuable to overcome common barriers to Six Sigma implementation. Moreover, the findings showed a strong alignment with the goals and practices of GE headquarters, which is an evidence of the quality culture that exists in GE and that allows all GE businesses achieve benefits with Six Sigma.

Originality/value

Since limited empirical research has been conducted concerning Six Sigma implementation in developing countries, this paper aspires to contribute to Six Sigma body of knowledge by illustrating the practices of a world benchmark corporation.

A morphological analysis of research literature on Lean Six Sigma for services

Purpose

The purpose of this paper is to review the existing literature on Lean Six Sigma (LSS) for services, construct a morphological analysis (MA) framework and identify research gaps to point to future research possibilities and priorities.

Design/methodology/approach

The MA framework is based on literature review of 175 papers published from 2003 to 2015, across 67 journals recognised by Scopus or ABS Academic Journal Quality Guide 2015. A three-phased methodology is used by the authors, with Phase1 featuring a five-stage systematic review protocol to identify relevant journal papers for review; Phase2 presenting a framework for classifying the reviewed papers in terms of their fundamental, methodological, chronological and sector-wise orientations; and Phase3 constructing an MA framework on the classified papers and identifying the research gaps.

Findings

The MA framework constructed based on six dimensions, namely, organizational context of applications, desired outcomes, implementation systems, LSS tools and techniques, integration with other management philosophies and evaluation methods, involving 40 focused themes, has revealed 355 distinct research gaps as opportunities for future research.

Practical implications

This paper confirms the existence of substantial scope and points to specific topics for further research in the area of LSS for services. The findings demonstrate the gaps in academic research on the subject. In addition, the study also helps organisational leaders and practitioners to look at LSS from a holistic perspective in the services context.

Originality/value

The MA framework of the existing literature on LSS for services presents a unique, systematic effort to identify research opportunities. In addition, a five-stage systematic review protocol is proposed in this paper. This could be valuable to researchers and practitioners in enabling them to systematically review the literature on research subjects of interest to them.

Integration of Taguchi and Shainin DOE for Six Sigma improvement: an Indian case

Purpose

The purpose of this paper is to demonstrate the application of Six Sigma/design of experiments (DOE) hybrid framework for improving damping force (DF) generation process in a shock absorber assembly unit.

Design/methodology/approach

The study adopted a case study research method with single case (holistic) design. This research design was found to be appropriate for testing the projected framework for integrating DOE approaches within Six Sigma define-measure-analyze-improve-control (DMAIC) cycle. In the proposed framework, Shainin’s component search technique (CST) was deployed at the “analysis” phase of DMAIC for the first stage filtering of process parameters, followed by the use of Taguchi orthogonal arrays (OA) at the “improve” phase for identifying the optimal setting of the parameters.

Findings

The application of Shanin CST facilitated in ascertaining that assembly component (piston with rebound stopper) was causing the variation and not the assembly process. Further, the use of Taguchi OA at the improve phase allowed the collection of necessary data to determine the significant piston parameters with minimum experimentation (eight experimental runs in this case as opposed to the expected 64) and analysis of variance on the collected data facilitated the selection of parameter settings to optimize the “critical to quality”, i.e. rebound DF.

Originality/value

This study provided a stimulus for wider application of integrated DOE approaches by the engineering community in the problem solving and the identification of parameters responsible for poor performance of the process.

Quantitative analysis of Six Sigma, Lean and Lean Six Sigma research publications in last two decades

Purpose

The purpose of this paper is to extend previous studies to a hybrid analysis of three business improvement practices of Lean, Six Sigma and Lean Six Sigma (LSS) within last two decades and identify the research gaps and focusses in more comprehensive and robust classification framework.

Design/methodology/approach

A secondary data collection and a literature review were conducted to collect information about peer-reviewed journal articles under six dimensions of a tested classification framework. The frequency and distribution analysis was conducted followed by Pearson’s χ2 test to analyse any relationship between dimensions of framework in order to identify the gap.

Findings

Despite a relatively great deal of regular research outputs about Six Sigma, Lean and LSS, academic journal articles have been found mainly limited to a few industries, themes and countries. “General manufacturing”, “healthcare”, “automotive” and “electronic industries” as sectors; and “tools and techniques”, “benefits” and “success factors” as key themes have been mostly approached by LSS, Six Sigma and lean management articles. It was also found that there is still a great disparity amongst researchers and journals to publish about these three business improvement practices.

Research limitations/implications

The research publications for LSS, Six Sigma and lean management should have wider approach towards various manufacturing and service sectors, countries and journal publications. A greater level of research/enterprise activities has been found in relation to LSS and Six Sigma articles compared to lean management articles.

Originality/value

This research aims to identify the gaps in research publications during last two decades about three major business improvement practices in one package and through more comprehensive robust classification framework and also through comparative analysis.

A new method to improve the objectivity of early Six Sigma analysis

Purpose

A process improvement sampling methodology, known as process variation diagnostic tool (PROVADT), was proposed by Cox et al. (2013). The method was designed to support the objectivity of Six Sigma projects performing the measure-analyse phases of the define-measure-analyse-improve-control cycle. An issue in PROVADT is that it is unable to distinguish between measurement and product variation in the presence of a poor Gage repeatability and reproducibility (R&R) result. The purpose of this paper is to improve and address PROVADT’s sampling structure by enabling a true Gage R&R as part of its design.

Design/methodology/approach

This paper derives an enhanced PROVADT method by examining the theoretical sampling constraints required to perform a Gage R&R study. The original PROVADT method is then extended to fulfil these requirements. To test this enhanced approach, it was applied first to a simulated manufacturing process and then in two industry case studies.

Findings

The results in this paper demonstrates that enhanced PROVADT was able to achieve a full Gage R&R result. This required 20 additional measurements when compared to the original method, but saved up to ten additional products and 20 additional measurements being taken in future experiments if the original method failed to obtain a valid Gage R&R. These benefits were highlighted in simulation and industry case studies.

Originality/value

The work into the PROVADT method aims to improve the objectivity of early Six Sigma analyses of quality issues, which has documented issues.

Employees factors importance in Lean Six Sigma concept

Purpose

– Lean management and Six Sigma concepts are derived from two different points of view, but it is evident that the role of employees is crucial in both concepts. The purpose of this paper is to survey which employees’ behaviour dimensions can lead organization to better concepts integration and how Lean Six Sigma activity contributes to employees’ performance.

Design/methodology/approach

– Research methodology is designed to empirically check, on large sample of companies in multinational company supply chain, if employees’ factors are both predictor and response variables of Lean Six Sigma concept. To check stated hypothesis factor, reliability and multiple regression analysis are used.

Findings

– The first finding of this study is that reward system and training are significant predictors of Lean Six Sigma activities. The second part of findings shows that Lean Six Sigma dimensions, such as Define, Measure, Analyze, Improve, and Control/Define, Measure, Analyze, Design, and Validate, 5S and Kanban positively influences employees’ performance, described by employee satisfaction, absenteeism, salaries and benefits, employees’ commitment and employee turnover rate.

Research limitations/implications

– Poka-Yoke application is not found as a significant predictor of employees’ performance. Accordingly, to explore that interesting finding, possible future research topic is more detailed analysis of Poka-Yoke application in similar supply chains. A longitudinal analysis using structural equation is possible direction of future work, too.

Practical implications

– This survey answers the need for Lean and Six Sigma unified methodology achievement in soft factors area and gives applicable results for companies in supply chain that produces low-volume, high-complexity products.

Originality/value

– Original and valuable conclusion is that employees’ factors are both predictor and response variables of Lean Six Sigma concept application.

Academic leadership and Lean Six Sigma

Purpose

– The purpose of this paper is to demonstrate the ability to researchers of using design of experiments (DoE) as a structured and systematic approach to performing systematic literature reviews. The authors demonstrate a simple case study illustrating the application of DoE in executing a systematic literature review on two popular topics in higher education: academic leadership and Lean Six Sigma.

Design/methodology/approach

– The methodology involves the systematic literature review of linking academic leadership with terms such as Lean, Six Sigma, Total Quality Management, Maturity Model and Continuous Improvement. The main tool used to structure the systematic literature review is a Taguchi Orthogonal Array design, specifically an L16 grid and the method is verified by conducting another review, replacing the term academic leadership with simply leadership.

Findings

– The approach identified at first no research papers linking the terms; however, when academic leadership was replaced with university, 19 research papers where discovered. The verification exercise, linking just leadership with the other search string generated over 1,000 results – demonstrating that the tool can find large volumes of articles if they exist, the search was completed for a ten year time frame – 2004 to 2014.

Research limitations/implications

– The case study focussed on a field which is known to have little current research and the verification exercise deliberately targeted a known large body of research. The authors will continue to use the approach and refine the technique over time.

Practical implications

– This approach would help any researcher despite of their discipline to identify opportunities and gaps in the current literature.

Originality/value

– The paper shows how DoE can be used in an academic research-based process. No other literature review approach currently exists which uses Taguchi approach to DoE to filter the search criteria.

The underlying factorial structure and significance of the Six Sigma difficulties and critical success factors

Purpose

– The purpose of this paper is to determine the underlying structure (latent constructs) of the difficulties and critical success factors (CSFs) of Six Sigma implementation in manufacturing companies. Determining the significance Greek manufacturing companies give to the Six Sigma difficulties and CSFs is also an aim of the present study.

Design/methodology/approach

– A research study was carried out in 91 ISO 9001 certified Greek manufacturing companies through a structured questionnaire. Exploratory factor analyses are applied to determine the underlying structure (latent constructs) of the Six Sigma difficulties and CSFs, while their significance is determined through descriptive statistics.

Findings

– Three latent constructs of Six Sigma difficulties are extracted, namely, “implementation patterns of Six Sigma methodology”, “absence of human interest and support”, and “low quality management level”. These difficulties are not considered very significant by the sample companies. Three latent constructs of Six Sigma CSFs are also extracted, namely, “understanding the implementation patterns of Six Sigma and its interface with the company”, “company culture and organisation”, and “prioritising Six Sigma projects based on stakeholders and company performance”. The role of these critical factors for the success of Six Sigma is very significant, according to the sample companies.

Research limitations/implications

– The small sample of the responding manufacturing companies, the diversity of the business sectors represented in the sample, and the subjective business evidence obtained from the company quality managers are the main limitations of the present study. Based on these limitations, future research studies are suggested.

Practical implications

– By eliminating the negative influence of the difficulties and simultaneously by enhancing the positive influence of the CSFs, a robust internal business environment can be created for the successful implementation of Six Sigma.

Originality/value

– This study fills the literature gap and contributes to the literature by determining the underlying structure and the significance of the Six Sigma difficulties and CSFs. This is the first research study in the field of Six Sigma that has been carried out in ISO 9001 certified manufacturing companies operating in the Greek business environment.

Improving ED specimen TAT using Lean Six Sigma

PURPOSE

Lean and Six Sigma are continuous improvement methodologies that have garnered international fame for improving manufacturing and service processes. Increasingly these methodologies are demonstrating their power to also improve healthcare processes. The purpose of this paper is to discuss a case study for the application of Lean and Six Sigma tools in the reduction of turnaround time (TAT) for Emergency Department (ED) specimens. This application of the scientific methodologies uncovered opportunities to improve the entire ED to lab system for the specimens.

DESIGN/METHODOLOGY/APPROACH

This case study provides details on the completion of a Lean Six Sigma project in a 1,000 bed tertiary care teaching hospital. Six Sigma's Define, Measure, Analyze, Improve, and Control methodology is very similar to good medical practice: first, relevant information is obtained and assembled; second, a careful and thorough diagnosis is completed; third, a treatment is proposed and implemented; and fourth, checks are made to determine if the treatment was effective. Lean's primary goal is to do more with less work and waste. The Lean methodology was used to identify and eliminate waste through rapid implementation of change.

FINDINGS

The initial focus of this project was the reduction of turn-around-times for ED specimens. However, the results led to better processes for both the internal and external customers of this and other processes. The project results included: a 50 percent decrease in vials used for testing, a 50 percent decrease in unused or extra specimens, a 90 percent decrease in ED specimens without orders, a 30 percent decrease in complete blood count analysis (CBCA) Median TAT, a 50 percent decrease in CBCA TAT Variation, a 10 percent decrease in Troponin TAT Variation, a 18.2 percent decrease in URPN TAT Variation, and a 2-5 minute decrease in ED registered nurses rainbow draw time.

PRACTICAL IMPLICATIONS

This case study demonstrated how the quantitative power of Six Sigma and the speed of Lean worked in harmony to improve the blood draw process for a 1,000 bed tertiary care teaching hospital. The blood draw process is a standard process used in hospitals to collect blood chemistry and hematology information for clinicians. The methods used in this case study demonstrated valuable and practical applications of process improvement methodologies that can be used for any hospital process and/or service environment.

ORIGINALITY/VALUE

While this is not the first case study that has demonstrated the use of continuous process improvement methodologies to improve a hospital process, it is unique in the way in which it utilizes the strength of the project focussed approach that adheres more to the structure and rigor of Six Sigma and relied less on the speed of lean. Additionally, the application of these methodologies in healthcare is emerging research.

An institutional theory of quality outcomes in strategic supply chain partnership

Purpose

– The purpose of this paper is to develop a theoretical base for buyer-supplier quality outcomes (in the context of a strategic partnership) from the institutional theory of the firm. It examines quality outcomes within a partnership and demonstrates how the partners’ quality outcomes are related.

Design/methodology/approach

– The paper examines quality outcomes within a strategic supply chain partnership (buyer-supplier) and demonstrates how the partners’ quality performance are related. Correlation analysis is used to examine the research hypothesis.

Findings

– Utilizing the institutional theory and stakeholder theory of the firm, it is argued that within a strategic partnership, the quality outcomes of the partners are significantly related. By focusing on a strategic alliance within a strategic group in the US airline industry, it is shown that there is a significant relationship among quality outcomes of the partners within the strategic alliance.

Research limitations/implications

– The analysis was limited to only one strategic partnership. Future research should examine quality outcomes among multiple strategic partnerships in order to validate the findings of this study.

Originality/value

– The study discusses the importance of strategic alliances and networks of firms as determinants of firm quality performance.

Critical failure factors of Lean Six Sigma: a systematic literature review

Purpose

– Lean Six Sigma (LSS) is a continuous improvement methodology that aims to reduce the costs of poor quality, improve the bottom-line results and create value for both customers and shareholders. The purpose of this paper is to explore the critical failure factors for LSS in different sectors, such as manufacturing, services, higher education, etc.

Design/methodology/approach

– The following research is based on a systematic literature review of 56 papers that were published on Lean, Six Sigma and LSS in well-known academic databases from 1995 to 2013.

Findings

– There are 34 common failure factors of LSS cited in this paper. There are some common factors for failure, such as a lack of top management commitment and involvement, lack of communication, lack of training and education, limited resources and others. Many gaps and limitations are discussed in this paper and need to be explored in future research.

Originality/value

– The paper is one of the first systematic literature reviews to explore the critical failure factors of LSS and discuss the top failure factors from different angles, i.e. countries’ evolution, organisations’ size (small- and medium-sized enterprises and large organisations) and industry nature.

A hybrid framework based on SIPOC and Six Sigma DMAIC for improving process dimensions in supply chain network

Purpose

– The purpose of this paper is to introduce a hybrid framework (suppliers, inputs, process, output and customers+define, measure, analyze, improve and control (SIPOC+DMAIC)) aimed at improving supply chain management (SCM) process dimensions in a supply chain (SC) network.

Design/methodology/approach

– Based upon the critical review of literature, process dimensions (average outgoing quality limit (AOQL), average outgoing quality (AOQ), process Z, defect per million opportunity) critical to SCM performance were identified. A framework consisting of three phases, i.e., design, implementation and results has been conceptualized and a case from paint industry is investigated. Implementation framework makes use of SIPOC model and Six Sigma DMAIC methodology. The goals of the study were achieved by using Six Sigma tools such as brainstorming sessions; root cause analysis, histograms, statistical tools such as control charts and process capability analysis.

Findings

– Authors made an attempt to propose a conceptual framework for improving process dimensions in a SC network. It is observed from the results that selection of appropriate strategies for improving process performance based upon experiences, and use of statistical tools by cross-functional teams with an effective coordination, guarantees success. Metrics such as AOQL shows the maximum worst possible defective or defect rate for the AOQ. Process Z helps to know about sigma capability of the process.

Research limitations/implications

– The framework so developed is tested in a single company manufacturing batches of paint. The study has important implications for the industry since it tries to integrate SCM process dimensions which would help in successful implementation of SCM practices in firm by following the DMAIC process. The framework enables the practitioners to investigate the process and demonstrate improvements using DMAIC which makes use of statistical tools.

Originality/value

– Although process dimensions related to SCM are critical to organization competitiveness, research so far has tended to focus on supply chain operations and reference model, balanced scorecard, total quality management, activity-based costing, just in time, etc., but in literature hardly any description of the SIPOC-DMAIC model to improve SCM process performance is provided. The use of statistics in DMAIC provides better insight into the process performance, and process control.

Optimization of multiple-quality characteristics in micro-WEDG process using Taguchi technique

Purpose

– Micro-EDM is an important process in the field of micro-machining. Especially, theμEDM is one of the technologies widely used for manufacture of micro-parts, micro-tools and micro-components, etc. The accuracy and repeatability of theμEDM process is still highly dependent on theμWEDG process. The electrode generation and regeneration is considered a key enabling technology for improving the performance of theμEDM process. Many engineers considered the Taguchi technique as engineering judgment during multiple response optimizations. This paper aims to focus on the use of micro-WEDG process to generate a micro-tool (electrode) with minimum surface roughness and higher metal removal rate (MRR).

Design/methodology/approach

– In this research work, the Taguchi quality loss function analysis is used to examine and explain the influences of three process parameters (feed rate, capacitance and voltage) on the output responses such as MRR and surface roughness. Further, the optimized machining parameters were determined considering the multiple response objective using Taguchi multi-response signal-to-noise ratio.

Findings

– Based on the experimental result, it was concluded that the Taguchi technique is suitable for the optimization of multi-response problem.

Originality/value

– This paper presents an alternative approach using Taguchi's quality loss function. In most of the modern technological situations, more than one response variable is pertinent to the success of an industrial process. In this research work, the influence of feed rate, capacitance and voltage on the MRR and surface roughness (multiple responses) is investigated.

Concise process improvement definition with case studies

Purpose

– The purpose of this paper is to examine the efficiency and objectivity of current Six Sigma practices when at the measure/analyse phase of the DMAIC quality improvement cycle.

Design/methodology/approach

– A new method, named process variation diagnostic tool (PROVADT), demonstrates how tools from other quality disciplines can be used within the Six Sigma framework to strengthen the overall approach by means of improved objectivity and efficient selection of samples.

Findings

– From a structured sample of 20 products, PROVADT was able to apply a Gage R&R and provisional process capability study fulfilling the pre-requisites of the measure and early analyse phases of the DMAIC quality improvement cycle. From the same sample, Shainin multi-vari and isoplot studies were conducted in order to further the analysis without the need of additional samples.

Practical implications

– The method was tested in three different industrial situations. In all cases PROVADT's effectiveness was shown at driving forward a quality initiative with a relatively small number of samples. Particularly in the third case, it lead to the resolution of a long standing complex quality problem without the need for active experimentation on the process.

Originality/value

– This work demonstrates the need to provide industry with new statistical tools which are practical and give users efficient insight into potential causes of a process problem. PROVADT makes use of data needed by quality standards and Six Sigma initiatives to fulfil their requirements but structures data collection in a novel way to gain more information.

Differences in Business Process Management Leadership and Deployment

Business Process Management (BPM) can improve organizational effectiveness and efficiency by optimizing the performance of cross-functional processes. Despite its potential, BPM deployment success has been mixed, due in part to the substantial changes required within the organization. Three changes considered necessary for BPM deployment success include a properly defined business process organizational infrastructure (complete with formal positions and competencies), boundary-spanning process ownership, and boundary-spanning process governance. However, given that BPM has largely been driven by practitioners, deployment details often vary by company. The present research examined the extent that these deployment details were industry related, and found significant differences between the manufacturing and service sectors in terms of organizational infrastructure and process ownership. These findings provide further evidence that a ‘one-size-fits-all’ approach to BPM does not exist, and that differences in BPM deployment decisions can be related to industry sector.