Alexander-Govern test using Winsorized means

Classical tests for testing the equality of independent groups which are based on arithmetic mean can produce invalid results especially when dealing with non-normal data and heterogeneous variances (heteroscedasticity). In alleviating the problem, researchers are working on methods that are more adapt to the aforementioned conditions which include a procedure known as Alexander-Govern test. This procedure is insensitive in the presence of heteroscedasticity under normal distribution. However, the test which employs the arithmetic mean as the central tendency measure is sensitive to non-normal data. This is due to the fact that the arithmetic mean is easily influenced by the shape of distribution. In this study, the arithmetic mean is replaced by robust estimators, namely the Winsorized mean or adaptive Winsorized mean. The proposed Alexander-Govern test with Winsorized mean and with adaptive Winsorized mean are denoted as AGW and AGAW, respectively. For the purpose of comparison, different Winsorization percentages of 5%, 10%, 15% and 20% are considered. A simulation study was conducted to investigate on the performance of the tests which is based on rate of Type I error and power. Four variables; shape of distribution, sample size, level of variance heterogeneity and nature of pairings are manipulated to create the conditions which could highlight the strengths and weaknesses of each test. The performance of the proposed tests is compared with their parametric counterparts, the t-test and ANOVA. The proposed tests show improvement in terms of controlling Type I Error and increasing power under the influence of heteroscedasticity and non-normality. The AGAW test performed best with 10% Winsorization while AGW test performed best with 5% Winsorization. Under most conditions (74%), AGAW tests outperform AGW tests. Therefore, the Winsorized mean and the adaptive Winsorized mean can significantly improve the performance of the original Alexander-Govern test. These proposed procedures are beneficial to statistical practitioners in testing the equality of independent groups even under the influence of non-normality and variance heterogeneity

Systematic Literature Review of Supply Chain Relationship Approaches amongst Business-to-Business Partners

Managing a business-to-business (B2B) supply chain relationship is an endless challenge. Many recent systematic literature review studies have discussed supply chain relationships from various perspectives. However, a comprehensive analysis, summarising the existing research, explicitly identified the implemented B2B supply chain relationships and found the effects of these relationships on supply chain performance remain lacking. To address the gap, this article presents a systematic literature review based on the PRISMA approach regarding the nature of the supply chain relationships between B2B partners and their effect on supply chain performance. Web of Science and Scopus were used in the compilation of studies published between 2000 and 2020. Findings indicate that the majority of B2B partners use a collaborative relationship approach and that the impacts are marked on the operational, financial, innovation, environmental, social and economic performance of their supply chain. This study seeks to contribute to the existing literature on B2B supply chain relationships by conducting a thorough and unbiased review of previous studies, drawing more general conclusions about the adopted supply chain relationships between B2B partners and providing insights for future research

End-of-Life Vehicle Management Systems in Major Automotive Production Bases in Southeast Asia: A Review

End-of-life vehicle (ELV) management is becoming increasingly important as the automotive industry is one of the world’s most critical sectors and is rapidly expanding. ELV management is essential for environmental protection and wellbeing under Sustainable Development Goal (SDG) 3, provides more jobs under SDG 8, and promotes a circular economy under SDG 11. All these factors contribute to the importance of ELV management as a research topic. Today, ELV management is well-positioned and an emerging research area particularly on ELV recycling systems in Europe, Japan, Korea, Taiwan and China. This paper aims to provide a review of ELV management in Malaysia, Thailand and Indonesia, which are the major automotive production bases in Southeast Asia, but which lack formal ELV recycling policies. Towards this end, the researchers have adopted a qualitative study in which document research has been used to analyze existing scientific studies and other published sources. The findings reveal that immature ELV management systems in Malaysia, Thailand and Indonesia are the reason that no specific ELV laws and regulations exist, as well as why there are no precise ELV statistics. Nevertheless, there have been growing concerns about ELV management, as evidenced by environmental regulations and programs aimed at better management of ELV recycling in these countries. These findings will assist the respective authorities in formulating specific laws and regulations that will ensure sustainable management of ELV and will also ensure a better life and economy for society and for industry

Cooperative Governance and Cooperative Performance: A Systematic Literature Review

Despite the proliferation of systematic literature review studies on cooperative organization, a similar review of cooperative governance and performance literature has yet to be conducted. To close this gap, this paper presents a systematic literature review on the relationship between cooperative governance (CG) and cooperative performance using the PRISMA approach. Major search engines were used in the compilation of studies published between 2009 and 2021. A review of the 30 selected papers indicate there are four categories of CG used in relation to cooperative performance: board characteristics, policy compliance, management, leadership and strategies, and the board’s social or human capital. The results also suggest mixed and inconclusive findings on the CG–cooperative performance relationship. The current study seeks to contribute to the existing literature by highlighting patterns and gaps of past studies on the CG–cooperative performance relationship, thereby providing insights for future research