Impact of COVID 19 on the demand for an inventory model under preservation technology and advance payment facility

Due to the COVID-19 epidemic, human civilization and the corporate world confront unfathomable risks to their continued existence on the planet. People all over the world are losing employment or seeing their incomes diminish due to the COVID-19 virus influence. As a result, its influence has a direct effect on the purchasing ability of consumers. When a customer's purchasing capability is diminished, his desire for items decreases. Again, retailers or suppliers of deteriorative goods face a risk in this uncertain environment, since deteriorative products have a limited shelf life. They should have an appropriate business strategy in this circumstance to maintain their commercial profession. Taking all of these factors into account, an inventory model is created that incorporates the COVID-19 influence on consumers' demand for perishable commodities with preservation capability. Customers are granted a partial trade credit term to enable them to sell the items on time. The proposed model is very intricate and not amenable to an analytical solution. Two numerical cases are explored and solved to demonstrate the proposed model's practical usefulness. The eigenvalues of that numerical example are determined to demonstrate that the Hessian matrix is positive definite, i.e., to determine the average cost function's convexity. Finally, we do a post-optimality study to find out how different inventory characteristics affect the best policies.

Impacts of green and preservation technology investments on a sustainable EPQ model during COVID-19 pandemic

Carbon and Sulfur dioxides emissions are the key issues of global warming that affects on human health. Emissions cap- and -trade policy is a key mechanism implemented in several countries to reduce the emissions. Nowadays, public gathering is restricted due to the pandemic situation caused by COVID-19. As a result, people are facing huge problems in their regular activities and lifestyle. During the lockdown periods, demands for few merchandises decrease and the deterioration rate increases. Moreover, because of the unavailability of raw materials and labours during the lockdown, shortages occur at the manufacturing company. Keeping these problems in mind, a multi-objective sustainable economic production quantity model is proposed with partially back-ordering shortages, in which the effects of sustainability are investigated. To handle the demand fluctuation throughout the current pandemic, emergency level dependent demand rate is assumed. To reduce greenhouse gases emissions and deterioration rate, investments in green technology and preservation technology efforts are used. The objectives of this study are to maximize the manufacturera s profit and minimize the greenhouse gases emissions for producing green products. The multi-objective model is solved by utilizing the fuzzy goal programming approach. The mathematical model is illustrated by four numerical examples. The main finding of the work is that under both green and preservation technologies investments, a sustainable model with partially back-ordering shortages and lockdown level dependent demand rate decreases justifiable greenhouse gases emissions and increases the producta s greening level. The results indicate that the system profit is increased by 16.1% by investing in both preservation and green technology. Furthermore, a sensitivity analysis is performed along with some managerial insights for practitioners. Finally, the paper is ended with conclusions and future research tips. ©

A resilient hybrid payment supply chain inventory model for post Covid-19 recovery.

The present Covid-19 pandemic causes disruptions to markets and businesses in general, affecting the supply chain inventory system most significantly. This work investigates a hybrid payment inventory model considering inflation, cash discount, price-sensitive demand, and preservation technology investment for non-instantaneous deteriorating products. Due to the economic downturn, a hybrid payment scheme composed of multiple prepayments and a delay in payment is proposed to facilitate post Covid-19 recovery. The proposed model is one of the first models to consider a hybrid payment scheme in view of the Covid-19 pandemic, and to provide guidelines to retailers in planning the selling price, replenishment period, and preservation investment in view of the pandemic situation. The hybrid payment policy is suggested during the financial crisis to sustain orders from a retailer to the supplier and from the consumers to the retailer. During the supply disruptions, two cases for shortages and without shortages are studied. The nonlinear model is solved by Lingo 17 software. This study shows the effect of advance and delayed payments on the retailer's total profit. It also shows that the total profit is extremely delicate to the inflation rate. The numerical examples illustrate the inventory model for different scenarios. Sensitivity analysis is carried out to provide managerial insights to management during post Covid-19 recovery.