Sourcing decisions with uncertain time-dependent supply from an unreliable supplier

Recently, an increasing number of companies have encountered random production disruptions due to the COVID-19 pandemic. In this study, we investigate a two-stage supply chain in which a retailer can order products from a low-price ("cheap”) unreliable supplier (who may be subject to an uncertain production disruption and partially deliver the order) and an "expensive” reliable supplier at Stage 1 and a more "expensive” backup supplier at Stage 2. If the disruption happens, only the products that were produced before the disruption time can be obtained from the unreliable supplier. It is found that in the case with imperfect demand information updating, the unreliable supplier is always used while the reliable supplier can be abandoned. The time-dependent supply property of the unreliable supplier reduces the retailer's willingness of adopting the dual sourcing strategy at Stage 1, compared with the scenario with all-or-nothing supply. Different from the case with imperfect demand information updating, either the reliable or unreliable supplier can be abandoned in the case with perfect demand information updating. We derive the optimal ordering decisions and the conditions where single sourcing or dual sourcing is adopted at Stage 1. We conduct numerical experiments motivated by the sourcing problem of 3M Company in the US during the COVID-19 and observe that the unreliable supplier is more preferable when the demand uncertainty before or after the emergency order is higher. Interestingly, the retailer tends to order more from the unreliable supplier when the production disruption probability is larger in some cases. © 2022 The Author(s)

Knowledge ecosystem of financial markets: a new perspective on alleviating the supply-demand contradiction of the rural finance in the post-COVID-19 era

Purpose: This paper aims to establish a systematic cognition to alleviate the supply–demand contradiction in rural financial markets from an integrated perspective of knowledge management and proposes the concept of rural financial knowledge ecosystem (RFKE) to encourage multifaceted solutions. Design/methodology/approach: The authors qualitatively describe the process that the knowledge management dilemmas cause the supply–demand contradiction in the rural finance and further summarize a systematic methodology from three dimensions: the knowledge subject, the knowledge environment and the knowledge ecology. Findings: The authors list four types of knowledge management dilemmas leading to the supply–demand contradiction in the rural finance, i.e. the weak knowledge sharing, the poor knowledge flow, the slow knowledge updating and the imperfect knowledge environment. Meanwhile, the RFKE model consisting of the ecological subject, the ecological environment and the ecological regulation is also presented. Research limitations/implications: The role of knowledge management in improving the allocation of financial resources to various rural financial market participants (government, rural financial institutions, farmers, agricultural enterprises, etc.). Originality/value: The authors creatively give the RFKE model, which complements and enriches the theory of knowledge management. Meanwhile, relevant management practices are urgently needed under the macro circumstance of the COVID-19 pandemic and the rural revitalization in China. © 2022, Emerald Publishing Limited.

Impact of Covid-19 on shipbuilding and shipping industry

Covid-19 has been affecting the world for more than two years. The maritime sector in general has been hit hard by the pandemic as well. Since most of the world trade is carried out by sea transportation, the sector has been suffering deeply. The supply and demand chain were broken due to preventive measures such as lock-downs, travel restrictions etc. have been imposed the governments. Passenger transportation by sea was affected as well. As a result of all these the demand for ships and in turn for new buildings was dipped. Some of the shipyards got into trouble completing their ongoing projects due to financial difficulties even bankrupted. This paper deals with the problems that were surfaced during pandemic in maritime industry and for possible remedies to get out of it. Along with the global review of the impact of the pandemic, the effects on Turkish shipbuilding was also taken into consideration. © 2023 the Author(s).

Formation a Sustainable Supply Chain Strategy

The functioning of existing logistics supply chains was disrupted by the COVID-19 pandemic, the consequences of which have not been overcome yet. The crisis was caused by the termination of logistics operations as a result of lack of resources, as well as long delays in the supply of products from suppliers and logistics partners. The cardinal transformations which are taking place in the supply chains are also associated with the transition of all logistics operations to the digital environment. The purpose of the study is to develop a strategy for the formation of a sustainable supply chain that more comprehensive responds and effectively overcomes external influences. Redesigning of the global network, setting of the new parameters for supply chain buffers, and proactive supplier's management are aimed to overcome external influences. Rapid response to emerging logistics chain failures is achieved through end-to-end supply management, the use of an artificial intelligence-based risk management system, and planning based on forecasting, modeling and scenario development. The application of the proposed strategy for the creating of a sustainable supply chain will improve the level and quality of customer service, increase the revenue and reduce risks through the cost savings. The developed strategy for the formation of a sustainable supply chain will allow not only to monitor ongoing processes at any time, but also to correct possible changes in order to maintain the sustainability of the supply chain. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

UTILIZING TRANSIENT MODEL FOR SIMULATING UNCERTAINTY OF NATURAL GAS TRANSPORTATION SYSTEMS

High pressure fluctuations in gas transmission network is an extensive problem that leads to ineffective planning of gas management. Several studies are required to ensure pipeline integrity and safety limit remain intact. This paper investigates demand uncertainty factor and propose mitigation to solve high pressure fluctuation issue. A hydraulic steady state simulation is carried out using Pipeline Studio that computes time variant pressure output by considering flow, temperature and initial pressure profile for specific boundary and network element set points. Using sensitivity analysis result for gas flow equation and equation of state, the simulation is carried out for transient condition by using Movement Control Order (MCO) scenario due to pandemic COVID 19 as case study. Pressure trends obtained by running simulation on above case study are collected and compared with maximum operation pressure limit in pipelines. Result successfully concludes simulated pressure achieved is 61.87 barg with overall percentage of error by 0.31%. Study encourages future work to integrate simulation of gas and electricity to minimise uncertainty effect of gas demand to future proof the safety and reliability of pipeline system. © School of Engineering, Taylor's University.

Using cloud manufacturing to establish an ecosystem network for COVID-19 ventilator production

Cloud Manufacturing (CMfg) as a service-oriented manufacturing (SOM) paradigm promotes the paradigm of partnership and collaboration among the globally distributed resources. Like technology-based marketplaces, it can identify different suppliers, determine their available services, and assign them to the requested orders based on the service-demand matching mechanism. The dominant capabilities of the SOM as a service can provide a collaborative and flexible manufacturing network configuration. This paper has focused on developing a new CMfg architecture with a concentrating on collaborative concepts to elaborate the modular manufacturing through the virtual process. In this model, different parts of the customized products can be designed as modules produced by distributed suppliers. A (Formula presented.) representation model for the SOM system has been proposed by this architecture. The proposed architecture is enriched by the help of novel technologies presented in Industry 4.0 (I4.0). The model's performance can be evaluated through different approaches, like topology analysis. Furthermore, to simulate a modeling procedure of the architecture, the process of the ventilator production marketplace is discussed in Tehran, Iran. The capabilities of the model analysis to configure the CMfg network and fulfilling the demands have also been described. © 2023 Informa UK Limited, trading as Taylor & Francis Group.

Working from home vs working from office in terms of job performance during the COVID-19 pandemic crisis: evidence from China

Despite being a worldwide disaster, the COVID-19 pandemic has also provided an opportunity for renewed discussion about the way we work. By contextualizing in the early periods of China's ending of lockdown policy on COVID-19, this paper offers evidence to respond to an essential discussion in the field of working from home (WFH): In terms of job performance, can WFH replace working from the office (WFO)? The present study compares job performance in terms of quality and productivity between WFH and WFO from 861 Chinese respondents using entropy balance matching, a quasi-experimental methodology. Results reveal that WFH enhances job performance in terms of job quality but lowers it in terms of job productivity. In addition, the present study aims to capture and empirically measure the variations in fundamental job characteristics in terms of job control and job demand between WFH and WFO by applying the job demand control support model. More specifically, we find that job control items, such as ‘talking right' and ‘work rate', and job demand items, such as ‘a long time of intense concentration' and ‘hecticness of the job', are vital factors that contribute to how these differences exert influence on employees' performance in the context of the pandemic. © 2022 Australian Human Resources Institute (AHRI).

Flight reliability during periods of high uncertainty

In times of great uncertainty for the airline industry, travelers are in search of reliable itineraries now more than ever. With condensed airline schedules and less options, air travelers must rely on making flight connections and manage layover times to arrive at their final destination on time. In an era with readily available information, passengers expect accurate and transparent reliability information to help improve decision making for multi-leg itineraries. However, often for reliability in air travel, this information is incomplete or not useful. In this paper we utilize historical probability distributions of flight arrival and departure times using publicly available data to give an intuitive and predictive flight itinerary reliability metric. The COVID-19 pandemic significantly affected air-travel in the US and this uncertainty is still being felt with cancellations and delays due to staff shortages and reduced demand. Therefore, we extend the stochastic network model from our previous research to air travel during COVID-19 to see the effects on flight reliability. Using this model, we conduct computational experiments to evaluate air travel through multiple reliability metrics. We show that during periods of high uncertainty, predictive historical distributions of flight data considering recency and seasonal effects are less accurate given many cancellations and a reduced flight schedule. © 2022 Elsevier Ltd

Economic Policy Uncertainty, COVID-19, and Tourist Stays in Croatia: Evidence from a Fourier Toda-Yamamoto Modeling Approach

This study extends the literature with respect to economic policy uncertainty measures and tourism flows to Croatia through the use of the Toda and Yamamoto modeling approach with a Fourier approximation to capture structural breaks. The results show that domestic economic policy uncertainty does not have a significant impact on tourist overnight stays. However, an increase in European economic policy uncertainty reduces total and domestic tourist overnight stays. An increase in COVID-19 cases has a negative and significant impact on total, domestic, and foreign tourist overnight stays, and contributes to increases in both Croatian and European economic policy uncertainty. © 2022 Taylor & Francis Group, LLC.

The impact of COVID-19 on route-level changes in transit demand an analysis of five transit agencies in Florida, USA

This study examined the impacts of COVID-19 on changes in route-level transit demand across five transit agencies in the state of Florida. Data for 120 routes from five transit agencies were used to develop two-stage instrumental variable models. Data from January of 2019 to December of 2020 were used in the analysis. Routes that served a greater mix of land-uses experienced a smaller decline in ridership. The impacts of several other land-use variables were, however, not consistent across the five transit agencies. Fare suspension was estimated to have a positive impact on ridership. In contrast, occupancy reduction measures (to promote social distancing within the transit vehicle) had a very strong negative impact on demand. The magnitude of the negative impact of occupancy reduction was larger than the positive impacts of fare suspension. Extending this analysis to a larger set of routes across more agencies would be useful in enhancing the robustness of the findings from our models. Extending our analysis to include data from 2021 and later to capture the recovery phase is also an important direction for future work. © 2022

Automation and redistribution of work: the impact of social distancing on live TV production

The TV industry has long been under pressure to adapt its workflows to use advanced Internet technologies. It also must face competition from social media, video blogs, and livestreaming platforms, which are enabled by lightweight production tools and new distribution channels. The social-distancing regulations introduced due to the COVID-19 pandemic added to the list of challenging adaptations. One of the remaining bastions of legacy TV production is the live broadcast of sporting events and news. These production practices rely on tight collaboration in small spaces, such as control rooms and outside broadcast vans. This paper focuses on current socio-technical changes, especially those changes and adaptations in collaborative practices and workflows in TV production. Some changes necessary during the pandemic may be imposed, temporary adjustments to the ongoing situation, but some might induce permanent changes in key work practices in TV production. Further, these imposed changes are aligned with already ongoing changes in the industry, which are now being accelerated. We characterize the changes along two main dimensions: redistribution of work and automation. © 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.

Electrochemical oxidation of the increasingly used disinfectant benzalkonium chloride

Benzalkonium chloride (BAC) is a key ingredient in many cleaning and disinfectant products due to it being an effective antiviral and biocidal agent. Because of its prolific use, especially following the recent global COVID pandemic, increased levels of BAC have been found in the environment, in particular, in wastewater, where it has negative impacts due to its toxicity. This necessitates an effective treatment for BAC in wastewater to reduce its toxicity. In this work, electrochemical oxidation of BAC on a boron-doped diamond anode was studied to successfully remove BAC. The electrochemical measurements performed at different current densities confirmed that BAC was completely oxidized within 20 min of treatment at 50 mA/cm2. However, chemical oxygen demand (COD) measurements showed that around 50% of the initial BAC was completely mineralized after 1 h of degradation at 50 mA/cm2, while the remaining electrooxidation of BAC resulted in the production of transformation products. © 2023 Canadian Society for Chemical Engineering.