Multi-project Optimal Scheduling Considering Reliability and Quality Within the Construction Supply Chain: A Hybrid Genetic Algorithm

Although the construction industry, especially because of its relationship with other economic sectors, is one of the most important sectors that plays a key role in a country's economic growth, the construction supply chain has been considered less attention. Therefore, construction supply chain network design is of great importance for not only the companies but also governments. Thus, presenting an original mixed integer linear programming model, this paper introduces an optimal framework for a multi-project multi-resource multi-supplier construction supply chain network design for large construction companies with a decentralized procurement strategy. The main objective is to design a reliable supply chain model based on the quality of projects under the certain predefined budget, considering the entire supply chain as a single entity. Using a bi-objective approach to formulate the chain and the Lp-metric approach to solve the problem, make it possible to obtain a single-objective structural framework to reliability-quality trade-off consideration. To solve the problem in small and medium scales, GAMS software is employed, and a hybrid algorithm based on Genetic Algorithm (GA) and Simulated Annealing (SA) algorithm is developed to solve the large-scaled problem. The results show the capability of the model to attain optimal size of the chain as well as the quality-reliability trade-off considering a pre-specified budget. And, to the best of authors knowledge this is the first to obtain such a structured integrated framework in the construction supply chain

Environmental, social and economic growth indicators spur logistics performance: from the perspective of South Asian Association for regional cooperation countries.

This article examines the association between green logistics operations, social, environmental and economic indicators of SAARC (South Asian Association for Regional Cooperation) countries. The research used GMM (Generalized Method of Moments) and FGLS (Feasible Generalized Least Squares) two methods to tackle the problems of heterogeneity, serial correlation and heteroskedasticity. The findings show that fossil fuel consumption is at the heart of logistics operations; the more fossil fuel and non-green energy resources that are used, the more negative effects on society and environmental sustain-ability result from this. A lower quality of transport-related infrastructure and logistics services is negatively correlated with fossil fuel usage, carbon emissions, health expenditure, greenhouse gas emissions and political instability of SAARC countries. Conversely, efficient customs procedures and greater information sharing among supply chain partners increase trade opportunities and also improve environmental sustainability in terms of minimum carbon emissions due to the shorter waiting and queue times involved. Further, the application of green energy resources and green practices can mitigate negative effects on social and environmental sustainability due to better logistics operations while improving financial performance in terms of higher GDP per capita, trade openness and greater export opportunities around the globe. As there is very limited research using green practices relationship with macro-level indicators in current literature, this research will assist both practitioners and policy makers to understand the roles of green supply chain and green logistics in enhancing environmental sustain-ability, social improvement and economic growth for a better future.N/

A ROBUST BI-OBJECTIVE UNCERTAIN GREEN SUPPLY CHAIN NETWORK MANAGEMENT

Conflicting objectives becomes a common issue in many supply chain network optimization problems. In this paper, a new model is formulated to design a green supply chain network through a new mixed integer linear programming problem. Uncertain demand and stochastic environmental respect levels are the main parameters of the formulation. The first objective function minimizes the cost of the supply chain while the second objective function minimizes CO2 emission. Conditional Value at Risk (CVaR) approach is adapted to deal with demand uncertainty and the stochastic CO2 emission level. Finally, the model outputs and its results discussion are illustrated through a numerical example

Robust Bilevel Optimization for an Opportunistic Supply Chain Network Design Problem in an Uncertain and Risky Environment

This paper introduces the problem of designing a single-product supply chain network in an agile manufacturing setting under a vendor managed inventory (VMI) strategy to seize a new market opportunity. The problem addresses the level of risk aversion of the retailer when dealing with the uncertainty of market related information through a conditional value at risk (CVaR) approach. This approach leads to a bilevel programming problem. The Karush-Kuhn-Tucker (KKT) conditions are employed to transform the model into a single-level, mixed-integer linear programming problem by considering some relaxations. Since realizations of imprecisely known parameters are the only information available, a data-driven approach is employed as a suitable, more practical, methodology of avoiding distributional assumptions. Finally, the effectiveness of the proposed model is demonstrated through a numerical example. (original abstract

Project Stakeholder Management

This study aims to critically review the literature on Project Stakeholder Management (PSM) and motivation. This study contributes especially to the recent literature, on the topic shedding light on new insights regarding the PSM concept. Although many researchers have grappled with the applications of PSM methods in construction projects, scattered studies need to be summarized, coordinated, and analyzed with a comprehensive view. The research at hand is provided to fill this gap; focusing on the applications of mathematical approaches may be useful to further extend the concept

Optimization for Project Quality Management

In this chapter, the literature on mathematical optimization of the quality of construction projects is systematically reviewed. Despite the existence of review articles on time–cost–quality trade-off problems in the research background, so far no research emphasizes only the review of mathematical modeling of the quality dimension of the construction projects. Besides, no research explains the mathematical details of modeling, solution approaches, and their extension process. This chapter is organized to cover these research gaps and proposing some potentials for further extension of the concept

Examining the Energy-Environmental Kuznets Curve in OECD Countries Considering their Population

This research aims to examine the validity of the Environmental Kuznets Curve (EKC) hypothesis in 37 Organization for Economic Co-operation and Development (OECD) countries over the period from 1960 to 2019. Panel Quantile Regressions (QR) show that for the lower quartile, economic growth does not impact emissions; for the central quartile a U-shaped curve emerges; while for the upper quartile, an N-shaped curve is found. In addition, cointegrating regressions highlight that economic growth, fossil fuel consumption, and population exert a detrimental effect on the environment, while renewable energy consumption reduces carbon dioxide (CO2) emissions. These results are confirmed by panel causality tests since a feedback mechanism is found between CO2 emissions and the remaining series. Furthermore, single-country estimates provide evidence of great variability in the sample

Związek pomiędzy odpowiedzialnością społeczną firmy a jego sposobem działania

Background: This study investigates the relationship between CSR (corporate social responsibility) practices and enterprise performance. We have collected the data from 248 different enterprises located in different industrial areas of Karachi, mainly including S.I.T.E industrial area, Federal-B industrial zone, and West Wharf industrial area, Karachi Export processing zone, Bin Qasim industrial zone, and Korangi industrial zone. Methods: The study mainly employed SEM (structural equation modeling) to test hypotheses in AMOS software. The practices of CSR were measured through 'green design of products', 'ethical leadership', 'building school and hospital infrastructure', and 'environmental protection training'. Results: The findings revealed that ethical leadership is strongly and positively correlated with CSR practices, which confirmed that ethical leadership has strong potential to implement CSR practices inside and outside of the firms. The results further indicate that CSR practices enhance enterprise performance. Conclusions: This research provides insight into the relationship between CSR practices and enterprise performance. Further, this study will help senior managers, and practitioners to understand the significance of CSR practices.Wstęp: W pracy zaprezentowano analizę zależności pomiędzy praktykami CSR (społeczna odpowiedzialność przedsiębiorstwa) a sposobem działania przedsiębiorstwa. Zostały zebrane dane z 248 przedsiębiorstw zlokalizowanych w różnych przemysłowych obszarach Karachi, głównie w obszarze przemysłowym S.I.T.E, obszarze przemysłowym Federal-B, obszarze przemysłowym West Wharf, obszarze przetwórstwa Karachi Export, obszarze przemysłowym Bin Qasim oraz obszarze przemysłowym Korangi. Metody: W pracy zastosowano SEM (modelowanie strukturalne) dla testowania hipotez za pomocą programu AMOS. Stosowanie praktyk CSR było oceniane poprzez "zielone zaprojektowanie produktu", "przywództwo etyczne", "budowanie infrastruktury szpitalnej i szkolnej" oraz "kształcenie w obszarze ochrony środowiska". Wyniki: Otrzymane wyniki wykazały, że przywództwo etyczne jest silnie pozytywnie związane z praktykami CSR, co potwierdza, że etyczne przywództwo posiada silny potencjał wdrożenia praktyk CSR w ramach firmy oraz w jej otoczeniu. Wyniki wskazują również, że praktyki CSR wzmacniają działanie przedsiębiorstwa. Wnioski: Zaprezentowane w pracy badania wskazują na zależność pomiędzy praktykami CSR oraz sposobem działania przedsiębiorstwa. Dodatkowo, są one pomocą dla zarządzających wyższego szczebla dla zrozumienia istotności praktyk CSR