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A dynamic programming approach to optimal pollution control under uncertain irrevesibility : the poisson case
No full textInternational audienceWe solve a bimodal control problem with a non-concavity and certainly through a Poisson process underlying the transition from a mode to another. We use a dynamic programming approach and are able to uncover the global optimal dynamics (including optimal non-monotonic paths) under a few linear-quadratic assumptions, which do not get rid of the non-concavity of the problem. This is in contrast to the related literature on pollution control under irreversibility which usually explores local dynamics along monotonic solution pahs to first-order Pontryagin conditions
Meta-heuristics for sustainable supply chain management: a review
No full textInternational audienceDue to the complexity and the magnitude of optimisation models that appeared in sustainable supply chain management (SSCM), the use of meta-heuristic algorithms as competent solution approaches is being increased in recent years. Although a massive number of publications exist around SSCM, no extant paper explicitly investigates the role of meta-heuristics in the sustainable (forward) supply chain. To fill this gap, a literature review is provided on meta-heuristic algorithms applied in SSCM by analyzing 160 rigorously selected papers published by the end of 2020. Our statistical analysis ascertains a considerable growth in the number of papers in recent years and reveals the contribution of 50 journals in forming the extant literature. The results also show that in the current literature the use of hybrid meta-heuristics is overtaking pure meta-heuristics, the genetic algorithm (GA) and the non-dominated sorting GA (NSGA-II) are the most-used single- and multi-objective algorithms, the aspects of sustainability are mostly addressed in connection with product distribution and routing of vehicles as pivotal operations in supply chain management, and last but not least, the economic-environmental category of sustainability has been further noticed by the scholars. Finally, a detailed discussion of findings and recommendations for future research are provided
Deposit or reward: Express packaging recycling for online retailing platforms
No full textInternational audienceTo motivate consumers’ participation in recycling, we study two recycling policies for express packaging on an online retailing platform equipped with self-run logistics to collect express packaging from consumers. First, under the Deposit-Refund Policy (DRP), when consumers purchase from the platform, they pay a deposit for the express packaging, but the deposit will be refunded if they return the packaging to the platform. The other is the Recycling Reward Policy (RRP), under which the platform provides rewards when consumers return express packaging. The platform decides whether to recycle the express packaging and chooses the optimal recycling policy if recycling is economically feasible. To investigate, we first set up an optimization model to analyze these two recycling policies. Using the No Recycling Policy (NRP) as the benchmark, we then derive managerial insights through comparative analysis and numerical studies. Our results indicate that the consumers’ green consciousness plays a critical role in decision making. Specifically, NRP is optimal for the platform when the green consciousness level is low. As the consumers’ green consciousness level increases to a medium range, recycling becomes feasible and RRP is optimal. If the green consciousness level is high, DRP will be the optimal policy. These findings have helpful implications for corresponding decisionmakers (e.g., express industry managers, government departments) to cautiously judge whether to recycle express packaging and which recycling policy is best under different circumstances
Integrating bloodmobiles and drones in a post-disaster blood collection problem considering blood groups
No full textInternational audienceProviding safe and adequate blood in an emergency to save many lives can be a challenge to the health system. In addition to managing blood collection in crises, delivering blood to the crisis site in a timely manner is another important problem in decision-making. Hence, in this study, we present a bi-objective mathematical model for determining the routing of bloodmobiles and drones to collect blood from various blood group donors and apply a cross-match strategy to supply adequate blood in critical situations. The first objective function is to maximize the amount of collected blood while the second objective function is to minimize the maximum arrival time of vehicles to the crisis-stricken city. We also introduce a function that determines the time required for bloodmobiles to stay in one place for the blood-collection process so as to bring the problem closer to real-world conditions. The problem is formulated as a two-stage stochastic problem by considering uncertainty in blood demands and the number of donors. To demonstrate the applicability and the efficiency of the proposed model, the model is tested on data from a real case study and implemented in various sizes via CPLEX and MOPSO. Finally, the sensitivity analysis is performed on certain parameters. The results show that by adding bloodmobiles, the staying time of bloodmobiles in stations decreases, and the demands are met more rapidly. Also, for each drone added to the system that is responsible for transporting the collected blood to the disaster-stricken area, the amount of collected blood increases by 12% while the arrival-time of the last vehicle decreases by 46%. Therefore, this model can benefit decision-makers in times of crisis and the collection and timely delivery of blood to the crisis area
Striving to safeguard shareholders or maintain sustainability in periods of high uncertainty: A multi-country evidence
No full textInternational audienceThe significance of economic policies and their impact on corporate behavior and ecosystems are increasing in today's interconnected world. The purpose of this study is to assess the impact of economic policy uncertainty (EPU) on waste generation by firms and the impact of gender diversity on corporate boards on the relationship between EPU and waste generation. The study contributes to existing research related to ecological economics by investigating the impact of EPU on the level of waste generated by firms in China, Europe, and the US. Using a dataset of 8007 firm-year observations from 2002 to 2019, we find overwhelming evidence that EPU increases the level of waste produced, both hazardous and non-hazardous. This finding supports the “shareholders' wealth maximization” theory, which states that firms strive to safeguard shareholders during periods of high uncertainty. However, women directors, being more sensitive to sustainability, perform well on this front even during periods of high uncertainty, as the results show that gender-diverse boards significantly moderate the adverse impact of policy uncertainty on waste generation. However, the moderating impact of gender diversity is significant only for firms operating in environmentally sensitive industries. Our results are robust to different regression models, proxies for waste, and endogeneity issues
Simulation-Based Models of Multi-Tier Financial Supply Chain Management Problem: Application in the Pharmacy Sector
No full textInternational audienceA crucial role in the continuation of economic activities is played by the financing of services and production in supply chains. A key element of optimizing the financial flow of these complex networks is to pay attention to the financial aspects of these complex networks since they are becoming more and more complex and expanding. This study aims to investigate the supply chain of a pharmaceutical company’s holding company and its subsidiaries while using internal resource valuation to develop a new strategy for financing the company’s operations. There is a process of money circulation through the chain, which consists of passing through two treasuries (primary and secondary), which provide liquidity to compensate the deficits of some institutions with the excess liquidity of other institutions. In this article, we present three simulation-based models based on a case study conducted at Shafa Darou Investment Company in Tehran-Iran, a leading pharmaceutical investment company in the country, to examine the impact of implementing this idea in the real world. Considering the study’s results, it has been shown that the supply chain as a whole has improved in terms of its working capital. Using a set of local treasuries is generally associated with reducing risks and a greater level of stability when relying on the excess liquidity of chain members provided that financial independence from external institutions, such as banks, is maintained. In addition, if the members’ excess liquidity is deposited in a set of local treasuries rather than a bank, the profit and internal financial flow within the chain will be circulated throughout the chain, and more added value will be generated
Subtle activism: Heterotopic principles for unsettling contemporary academia from within
No full textInternational audienceResearch on academic activism tends to foreground vociferous and explicit forms of activism that pursue predefined political agendas. Against this backdrop, this article proposes that academic activism can take more subtle forms. Writing as an academic activist collective, we unpack what subtle activism might look like within the context of contemporary academia. We use Foucault’s concept of heterotopia to argue that subtle activism can expand the space of what is possible in academia today by experimenting with quietly unsettling norms rather than overtly opposing or rejecting them. We offer a set of principles that might underpin a subtle activist agenda, extrapolated from practices from colleagues and from own activist collective. We hope that these principles may serve to inspire other academics wishing to engage in subtle activism by unsettling everyday practices that discreetly challenge the status quo, thereby contributing to gently shifting the agenda for how it is possible to conduct intellectual work in the contemporary neoliberal university context
Why common job demands are challenging for individuals with mental illness: the interaction of personal vulnerability factors and ableist norms
No full textInternational audiencePurpose Drawing on the job demands-resources (JD-R) model, this study aims to examine which job demands individuals with diagnosed mental illness perceive to be most challenging as they navigate the workplace, why this is the case and which resources individuals tend to mobilize to meet these demands. Design/methodology/approach The authors draw on 257 qualitative surveys filled out by individuals with mental illness in various parts of the world. Findings The findings show that job demands that are common in today's workplace such as a high workload and a stressful environment are considered challenging by individuals with mental illness. Further, the authors show that this is the result of the ideal worker norm consisting of the need to be a steady performer that is confident, resilient and social with which the performer cannot comply on the one hand and the particularities of this population, such as performers' self-perceived low self-esteem, sensitivity to stress, fluctuating symptoms and difficulties with the social aspects of organizational life on the other hand. Originality/value The study points to the unique challenges of individuals with mental illness in the workplace and highlights the role human resource management (HRM) can play in providing support to allow this population to meet the demands of one's job more easily and thrive at work
How to deal with customer and supplier concentration to attain sustainable financial growth? The role of business strategy
No full textInternational audienceFor effective supply chain management, firms should focus on the relationship with their immediate stakeholders in the supply chain, namely, suppliers (upstream) and customers (downstream). This study investigates the impact of customer and supplier concentration as well as business strategy on sustainable financial growth, using financial data of 2021 Chinese non‐financial firms listed from 2006 to 2020. Additionally, it explores the moderating effect of business strategy on the relationship between customer and supplier concentration and sustainable financial growth. We find that higher customer and supplier concentration weakens the bargaining power of Chinese firms, which reduces their financial growth. However, an appropriate business strategy can help such firms achieve sustainable financial growth. We find that an aggressive business strategy moderates the negative impact of supplier concentration, while a defensive business strategy moderates the negative impact of customer concentration on financial growth. Finally, our results for the direct impact of customer and supplier concentration as well as business strategy hold for state‐owned and non‐state‐owned firms. However, we find differences regarding the moderating impact of business strategy between state‐owned and non‐state‐owned firms. Our results are robust to time and industry fixed effects, alternate proxies of financial growth and regression techniques
A dual perspective of organizational resilience (OR) and information technology systems resilience (ITSR): an analysis of interdependencies and tensions
No full textInternational audienceContemporary organizations face a rising incidence of disasters, extreme events and crises (Boin and Lodge 2021). In parallel, the socioeconomic landscape is increasingly complex which intensifies inter-organizational dependencies and the risk of cascading failures (Ansell et al. 2021). To survive and perhaps thrive, organizations must cultivate organizational resilience (OR). However, their capacity to do so is currently curtailed. Although it is widely recognized that the performance of organizational processes, functions and capabilities is closely aligned to the effectiveness of associated information technology systems (ITS) (Schultze and Orlikowski 2004); models of OR have yet to elucidate mechanisms by which ITS contribute to resilience capabilities (Annarelli and Nonino 2016). In this conceptual paper, which is a work in progress, we reflect upon the nature of interdependencies and tensions between ITS resilience (ITSR) and OR. We adopt a deductive, qualitative approach to systematically compare OR & ITSR. Our comparative analysis is informed by OR models described by Duchek (2020), Sheffi and Rice Jr (2005) and Weick and Sutcliffe (2011), while for ITSR, we employ the Reactive Manifesto as interpreted by Bonér et al. (2014) and Debski et al. (2017). Figs 1, 2 illustrate our interpretation of each resilience construct. As may be seen on Fig. 1 we interpret OR as a three-phase process including preemptive, proactive & recovery phases each possessing associated resilience capabilities. The process may occasion three operational outcomes (or levels of resilience maturity). 1st , 2nd and 3rd order resilience denote organizations that when a disruption occurs, merely maintain key operations, rapidly achieve a return to normal operations or that capitalize on a disruption to achieve an improved post-shock trajectory respectively. merely maintain key operations, rapidly achieve a return to normal operations or that capitalize on a disruption to achieve an improved post-shock trajectory respectively. ITSR is interpreted via the notion, reactive scalability which describes an organizational system that is both responsive and scalable (Debski et al. 2017) i.e., which is able to rapidly achieve (responsive) appropriately dimensioned (scalable) adaptations to intra and extra-organizational changes. Our analysis employs a multi-level approach. The preliminary results of the analysis are presented in Table 1. Upon completion of the analysis, we will elaborate theoretical propositions pertaining to the relationship between the OR and ITSR constructs to guide subsequent empirical research to bridge the theoretical divide between these in reality, indissociable resilience constructs. This comprises the main anticipated contribution