Search results

This paper aims to present the performance of deionized water in electrical discharge machining (EDM) during machining of Inconel 718, copper tool electrode and deionized water as dielectric. Three parameters, namely, pulse-on-time, pulse-off-time and discharge current were taken as control parameters with individual parameter having three levels. Influence of these control parameters on response such as tool wear rate (TWR), material removal rate (MRR) and surface roughness (Ra) is evaluated at various combinations of parametric levels. The results reveal deionized water can be effectively used as a sustainable dielectric and may substitute the hydrocarbon-based dielectric in electrical discharge machining. Also, the control parameters considered show significant impact on the process criteria. Super ranking method was adopted to achieve optimal integration of EDM control factors for obtaining higher MRR, lower TWR and Ra. Further, by applying analysis of variance test, discharge current is established as the dominant parameter during the machining process.

The experimentation was performed on Inconel 718 in SPARKONIX MOS, 35 A, ZNC EDM using deionized water as dielectric and copper tool as electrode. The dielectric circulatory system was developed without disturbing the existing dielectric circulation system. Figure 1 shows the EDM with newly developed dielectric system. The existing system consists of hydrocarbon-based dielectric, which has a number of drawbacks during the machining such as carbide deposition on the work material, which reduces removal of material from work material; carbon particle adhesion on tool, which results in inefficient discharge between the electrode; and the work material and production of CO and CH4 during machining, which makes the machining environment toxic. To overcome these drawbacks, a sustainable dielectric was adopted in present work. Trial experiments were conducted to select the ranges of parameters, namely, discharge current, pulse-on-time and pulse-off-time. The process characteristics were evaluated at different parametric combinations and the experimentation was designed as per Taguchi L9 orthogonal array. Table 1 shows the properties of Inconel 718. Table 2 shows the parameters considered with its ranges. Table 3 shows the experimental values. The difference of weight of work piece before and after was taken and divided by the machining time used for calculating the MWR. Similarly, the difference of weight of tool material before and after was taken and divided by machining time and is used for calculating TWR. Measurement of surface roughness was done using Talysurf surface roughness meter.

The experimentation was conducted at different parametric combination on Inconel 718 taking copper as electrode and deionized water as dielectric. The performance criteria was evaluated at considered parametric combination. The result shows that the EDM parameters have significant contribution on the performance criteria and deionized water can be effectively used as dielectric medium in EDM. The use of deionized water as dielectric will improve the process and sustainable green machining can be performed. Super ranking method has been implemented to achieve the best combination of control factors and it is obtained that the combination A1B1C3 (i.e. discharge current = 3 A, pulse-on-time = 1 µs and pulse-off-time = 3 µs) is best combination for obtaining the higher MRR and lower TWR and Ra. The contributing factor in the proposed research work is discharge current. Further, ANOVA was implemented to check the adequacy of these result. It was established that discharge current is the most influential factor followed by pulse-on-time and the least contributing factor as pulse-off-time. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining of difficult to cut materials such as Inconel 718 with sustainable dielectrics in engineering applications.

The paper is original in nature. The findings of this paper may open the guidelines for researcher for performing research in the field of sustainable machining.

The purpose of this paper is to demonstrate the role of livelihood assets, strategies and local social networks in disaster response and recovery in post-disaster setting of 2013 Kedarnath disaster (India).

It identifies post disaster macro-spaces of Mandakini river valley (India) using change detection analysis and secondary data. Within these macro-spaces, the micro spaces of livelihood and social capital were assessed by selecting two villages for case study.

Most important issues faced by communities were loss of lives, livelihoods and access to relief aid. A shift in economic base of families suffering loss of livelihoods was observed as they switched from pilgrimage-based to skill-based opportunities. Geographical location and isolation play a crucial role in recovery trajectory of villages by influencing the social capital.

The paper being case study based deals two of the worst-affected villages; livelihood strategies adopted and social network may be influenced by the “victim” status of villages and may not be generalized for each disaster-affected area.

Bridging and bonding networks were significant in geographically isolated places, while “linkages” were beneficial in bringing new livelihood opportunities. Need to enhance the role of social capital by institutional intervention in form of capacity building was required.

The study suggests focus on human capital-based livelihood diversification programs taking geographical location and disaster context into account.

This paper analyzes how information systems (IS) can serve as tools of neo-colonial control in offshore outsourcing of research and development work. It draws on critical work examining business and knowledge process outsourcing.

The paper reports an empirical study of how laboratory information management systems (LIMS) shape offshore outsourcing practices involving Western client firms and Indian contract research organizations (CROs) in the pharmaceutical industry. The study adopted a multi-actor perspective, involving interviews with representatives of Western clients, Indian CROs, system validation auditors, and software vendors. The analysis was iterative and interpretative, guided by postcolonial sensitivity to themes of power and control.

The study found that LIMS act as tools of neo-colonial control at three levels. As Western clients specify particular brands of LIMS, they create a hierarchy among local CROs and impact the development of the local LIMS industry. At inter-organizational level, LIMS shape relationships by allowing remote, real-time and retrospective surveillance of CROs’ work. At individual level, the ability of LIMS to support micro-modularizing of research leads to routinization of scientific discovery, negatively impacting scientists’ work satisfaction.

By examining multiple actors’ perceptions of IS, this paper looks beyond the rhetoric of system efficiency characteristic of most international business research. As it explores dynamics of power and control surrounding IS, it also questions the proposition that outsourcing of high-end work will move emerging economies upstream in the value chain.

This study aims to empirically examine the relationship between Six Sigma and organisational performance of the Dubai Police Force (DPF). Moreover, this study further explores the role of innovation culture as a mediating variable between this relationship.

A questionnaire survey was conducted to collect research data. The population of the study was composed of head section officers of the DPF. A total of 388 questionnaires were distributed amongst respondents in which 252 of them were returned. Structural equation modelling was performed to test the hypothesised model.

Central findings confirmed the effect of Six Sigma and innovation culture on organisational performance. Additionally, innovation culture was found to partially mediate the effects of Six Sigma on organisational performance.

Findings from this study may enlighten managers, practitioners and academicians on the importance of using Six Sigma in the policing field. This study advocates taking into account preparing appropriate culture when implementing Six Sigma projects given its role in facilitating the implementation of these projects and achieving success. Six Sigma with innovation culture provides a key opportunity for the creation of uniqueness and has the potential to significantly influence organisational performance.

This study adds to the current knowledge on the role of Six Sigma on organisational performance of police agencies. This study is the first to provide empirical evidence on the mediating role of innovation culture on the relationship between Six Sigma and organisational performance in policing context.

The overarching objective of this research is to integrate the Lean Six Sigma (LSS) framework with computer simulation to improve the production efficiency of a light-emitting diode (LED) manufacturing factory.

Recently, the idea of taking advantage of the benefits of Six Sigma and simulation models together has led both industry and the academy towards further investigation and implementation of these methodologies. From this perspective, the present research will illustrate the effectiveness of using LSS methodology in a real factory environment by using the combination of three simulation methods which are system dynamics (SD), discrete-event simulation (DES) and agent-based (AB) modelling.

The hybrid simulation method applied in this research was found to accurately mimic and model the existing real factory environment. The define, measure, analyse, control and improve (DMAIC)-based improvements showed that the applied method is able to improve machine utilization rates while balancing the workload. Moreover, queue lengths for several stations were shortened, and the average processing time was decreased by around 50%. Also, a weekly production increase of 25% was achieved while lowering the cost per unit by around 8%.

While the case study used was for a LED manufacturing system, the proposed framework could be implemented for any other existing production system. The research also meticulously presents the steps carried out for the development of the multi-method simulation model to allow readers to replicate the model and tailor it for their own case studies and projects. The hybrid model enables managers to navigate the trade-off decisions they often face when choosing advanced production output ahead of continuous improvement practices. The adoption of methodologies outlined in this paper would attain improvements in terms of queue lengths, utilization, reduced costs and improved quality and efficiency of a real, small factory. The findings suggest improvements and create awareness among practitioners for the utilization of quality tools that will provide direct benefits to their companies. Although the multi-method simulation is effective, a limitation of the current study is the lack of micro details within each station. Furthermore, the results are all based on one specific case study which is not enough to suggest and generalized findings.

This research combines the use of the three main hybrid simulation paradigms (SD, DES and AB) in a unified framework DMAIC methodology. Choosing the right models in DMAIC is important, challenging and urgently necessary. Also, this paper shows empirical evidence on its effectiveness.

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.