Search results

This paper aims to develop an initial understanding of the Lean Six Sigma methodology since its inception and examine the few Lean Six Sigma dimensions as a research domain through a critical review of the literature.

The paper is structured in two-part. The first part of the paper attempts to dwell on the evolution of the Lean Philosophy and Six Sigma methodology individually and the emergence of Lean Six Sigma methodology, covered under the Lean Six Sigma: a historical outline section. The second part of the study examines the dimensions associated with Lean Six Sigma such as frameworks, critical success factors, critical failure factors, type of industry, performance metric, year, publisher and journal, based on a total of 223 articles published in 72 reputed journals from the year 2000 to 2019 as a literature review.

The adoption of Lean Six Sigma, as a continuous improvement methodology, has grown enormously in the manufacturing and few service sectors such as health care and higher education during the past decade. The study revealed that researchers came out with conceptual frameworks for the implementation of Lean Six Sigma, whereas the validation through case studies seems to be lacking. The integration of Lean Six Sigma and other approaches with a focus on sustainability and the environment has emerged as a research field. A few of the most common critical success and failure factors were identified from the articles studied during the study.

This paper may not have included some of the studies due to the inaccessibility and selection criteria followed for the study.

This paper will provide an initial introduction on Lean, Six Sigma and Lean Six Sigma and research insights Lean Six Sigma to beginners such as students, researchers and entry-level professionals.

Evidence indicates that the Indian economy has grown enormously in recent years. and Lean Six Sigma (LSS) has evolved globally as a structured business improvement strategy with diverse applicability in the last fifteen years. Therefore, this paper aims to investigate the status of LSS implementation in Indian industries using a survey research technique.

A survey questionnaire was devised from the literature, containing 25 questions to assess respondents’ awareness of the LSS methodology and gain insights on aspects associated with LSS adoption in Indian industries. The survey questionnaire was validated and was conducted using randomly sampled respondents from the Confederation of Indian Industries membership database. The collected data were statistically analyzed using IBM SPSS and MS Excel.

The findings attest that adopting LSS is not so encouraging and extremely poor in small- and medium-scale Indian industries. ISO 9001 emerged as a prominent quality improvement program. It is learnt that consultants play a pivotal role in bringing awareness and skills building while implementing LSS. Results endorse top management commitment and involvement, and resistance to change as leading success factors and challenges, respectively. Further, it is revealed that respondents were highly satisfied after the adoption of LSS.

The findings of this study were derived from 183 responses and should be generalized cautiously.

This paper provides valuable insights on the present status covering the issues related to L:SS implementation in India. These results can motivate the managers of Indian industries for wide adoption of the LSS methodology. In addition, the findings of the paper may assist the researchers providing direction to carry out further research in LSS in the Indian context.

The purpose of this paper is to develop a framework for the safety performance measurement of belt conveyor systems.

A structural methodology of graph theory and matrix approach is used for developing a framework for safety performance measurement of belt conveyor systems.

The development of a framework for safety performance measurement of belt conveyor systems is essential for ensuring plant safety. For this, safety performance factors, including design and operating contextual factors of belt conveyor systems, are identified. The factors along with their interrelations are modeled using digraph. An equivalent matrix of the digraph provided safety performance function (SPF) of belt conveyor systems, leading to the development of a safety performance index (SPI).

The developed framework will enable the designers for evaluating and comparing alternative designs of conveyor systems from the safety viewpoint. The plant operators can make inferences from the SPI to identify the weak contextual factors in the plant and develop action plans for its mitigation.

The paper is novel and employs graph theory and matrix approach for safety performance measurement. The methodology helps in the quantitative evaluation of the safety performance of belt conveyor systems.

The purpose of this paper is to design and develop half-mode substrate-integrated waveguide (HMSIW)- and quarter-mode substrate-integrated waveguide (QMSIW)-based antennas for wireless communication application. The developed antennas offer advantages in terms of compactness, high gain and better isolation between the ports.

Initially, the tri-band substrate-integrated waveguide-based antenna is designed using a slot on the ground plane. Then, the same structure has been bisected into two parts for the development of the HMSIW structure. Again the concept of the slot is used for the realization of a dual-band antenna. QMSIW-based structure is designed with further dividing HMSIW structure into two parts. Simulation has been carried out with the use of a high-frequency structure simulator (HFSS) software, which used a finite element-based solver for the full-wave analysis.

The proposed HMSIW-based dual-band antenna resonates at two different frequencies, namely, 5.81 GHz with 4.5 dBi gain and at 6.19 GHz with 6.8 dBi gain. Isolation between two ports is 20 dB. The overall dimensions of the proposed model are 0.39 λ × 0.39 λ. Similarly, QMSIW-based antenna is resonated at 5.66 GHz of the frequency with the 3 dBi gain. Frequency tuning is also carried out with the change in the slot dimension to use the proposed antenna in various C (4–8 GHz) band applications.

The proposed antennas can use C band wireless frequency application. The proposed structure provides better performance in terms of isolation between the ports, small size, high front-to-back ratio and higher gain. It is fabricated for the proof of concept with the RT Duroid 5880 substrate material having a 2.2 permittivity. Measured results show a similar kind of performance as a simulated one.

In clinical analysis, medical image segmentation is an important step to study the anatomical structure. This helps to diagnose and classify abnormality in the image. The wide variations in the image modality and limitations in the acquisition process of instruments make this segmentation challenging. This paper aims to propose a semi-automatic model to tackle these challenges and to segment medical images.

The authors propose Legendre polynomial-based active contour to segment region of interest (ROI) from the noisy, low-resolution and inhomogeneous medical images using the soft computing and multi-resolution framework. In the first phase, initial segmentation (i.e. prior clustering) is obtained from low-resolution medical images using fuzzy C-mean (FCM) clustering and noise is suppressed using wavelet energy-based multi-resolution approach. In the second phase, resultant segmentation is obtained using the Legendre polynomial-based level set approach.

The proposed model is tested on different medical images such as x-ray images for brain tumor identification, magnetic resonance imaging (MRI), spine images, blood cells and blood vessels. The rigorous analysis of the model is carried out by calculating the improvement against noise, required processing time and accuracy of the segmentation. The comparative analysis concludes that the proposed model withstands the noise and succeeds to segment any type of medical modality achieving an average accuracy of 99.57%.

The proposed design is an improvement to the Legendre level set (L2S) model. The integration of FCM and wavelet transform in L2S makes model insensitive to noise and intensity inhomogeneity and hence it succeeds to segment ROI from a wide variety of medical images even for the images where L2S failed to segment them.

The purpose of this study is to examine the mediating role of manufacturing flexibility in the relationship between knowledge creation, technological turbulence and performance. In an increasingly competitive and changing environment, firms need to boost their technological and management know-how to adequately develop manufacturing flexibility.

This study analyzes survey data collected from 370 manufacturing firms. Validity and reliability analyses were conducted using SPSS and Amos. The research hypotheses were tested using covariance-based structural equation modelling.

The main findings show that knowledge creation positively and significantly affects business and operational performances directly, and indirectly, through manufacturing flexibility. Moreover, technological turbulence has a positive and significant effect on it. This finding contributes to understanding why some firms get better outcomes from manufacturing flexibility than others, a disputed issue in the literature.

This study highlights the need for manufacturing firms to foster cultures of knowledge creation, to better educate and train employees and to develop other instruments of knowledge creation.

This study makes several contributions to manufacturing flexibility literature: (1) establishing a link between technological turbulence and knowledge creation to develop manufacturing flexibility; (2) add empirical evidence on the relation between manufacturing flexibility and performance and (3) contributes to consolidating the mediation role of manufacturing flexibility in the relations between knowledge creation and business performance, as studies focussing on such a role are scarce in the literature.

The purpose of this paper is to study and analyse the behaviour of a magnetic fluid-based squeeze film between rotating transversely rough porous annular plates, taking the elastic deformation into consideration.

The stochastic film thickness characterizing the roughness is considered to be asymmetric with non-zero mean and variance and skewness while a magnetic fluid is taken as the lubricant. The associated stochastically averaged Reynolds-type equation is solved with appropriate boundary conditions to obtain the pressure distribution, which in turn is used to derive the expression for the load-carrying capacity.

It is observed that the roughness of the bearing surfaces affects the performance adversely, although the bearing registers an improved performance owing to the magnetic fluid lubricant. Also, it is seen that the deformation causes reduced load-carrying capacity. The bearing can support a load even in the absence of flow, unlike the case of conventional lubricants.

The originality of the paper lies in the fact that the negative effect of porosity, deformation and standard deviation can be minimized to some extent by the positive effect of the magnetic fluid lubricant in the case of negatively skewed roughness by suitably choosing the rotational inertia and aspect ratio. This effect becomes sharper when negative variance occurs.

The purpose of this paper is to evaluate the service quality automobile garages through development of a service quality index based on the factors influencing service quality.

A structural methodology of graph theory and matrix approach is applied for developing the service quality index.

The automobile maintenance can be considered as a service industry and in order to sustain in the competitive business environment, the service providers must ensure quality in their services. There are several factors that influence the service quality. Each factor is comprised of several sub-factors. Moreover, the factors are interrelated with each other. Modelling of these factors and their interrelations with due consideration of their structure is accomplished through the graph theory. The directed graph (digraph) of the service quality is defined; the nodes of this symbolize the quality influencing factors, while the edges represent their degrees of interrelationships. An equivalent matrix developed from the digraph establishes a service quality function which leads to evaluation of service quality index (SQI). A greater value of the service quality index displays that the organization and functioning of the garage is adequate.

The methodology can be applied for evaluating as well as comparing service quality of different garages. The observations would be helpful to the managers the garages to make strategies for improving their service quality.

The paper establishes the interrelations among various factors that influence the service quality at automobile garages and develop a numeric index for the evaluation of the same.

The lean and global character of supply networks today opens supply chains to potential disruptions, especially in volatile environments. Most disruptions are of relatively low potential impact; however, firms also occasionally face high-impact disruptions that may even threaten survival. This study applies and extends absorptive capacity concepts to organize resilience capabilities identified in the literature and to examine whether capabilities that provide low-impact resilience are different from those that provide high-impact resilience. A second and related objective is to evaluate whether low-impact resilience supports high-impact resilience through “learning by experience.”

Survey and industry data are used to understand capabilities involved with achieving both low-impact resilience and high-impact resilience.

The results of our analysis of survey and industry data uncover significant complex interactions in the effects of capabilities and volatility on resilience; suggesting that different absorptive capacity capabilities are related to low-impact resilience and high-impact resilience, respectively, and these effects depend on industry context. Moderating influences of exploitation capability and environmental volatility are consistent with a “learning by experience” explanation of the association of low-impact resilience to high-impact resilience.

This study thus provides a unifying framework with which to consider resiliency capabilities. Further, it answers a question raised in prior research, and it extends our understanding of important relationships between capabilities for different levels of resilience.

This paper aims to investigate the performance of a ferrofluid-based hydrodynamic journal bearing system.

This paper presents a new design of ferrofluid-based hydrodynamic journal bearing. An experimental set-up consisting of a magnetic shaft along with a brass bearing was modified and developed. A permanent magnet was used to make the selected shaft material magnetic. The load and speed were varied to conduct the analyses for different test conditions.

The paper provides information about a design of ferrofluid-based journal bearing and its improved performances. For moderate to higher loads at different shaft speeds, it was found that because of the magnetization effect, the maximum film pressure in case of a ferrofluid lubricant increased up to approximately 60 per cent, compared with that of the conventional lubricant-based journal bearing system. Besides, the temperature rise was found smaller for ferrofluid lubricants, thus making the system cooler while running.

This paper offers a new design of magnetic bearing system for the experimental analysis by utilizing a magnetic shaft with a non-magnetic bearing. The present ferrofluid-based bearing design is less complicated from manufacturing point of view.