Ordering Cost Depletion in Inventory Policy with Imperfect Products and Backorder Rebate

This study presents an inventory model for imperfect products with depletion in ordering costs and constant lead time where the price discount in the backorder is permitted.The imperfect products are refused or modified or if they reached to the customer,returned and thus some extra costs are experienced.Lately some of the researchers explicitly present on the significant association between size of lot and quality imperfection.In practical situations,the unsatisfied demands increase the period of lead time and decrease the backorders.To control customers'problems and losses,the supplier provides a price discount in backorders during shortages.Also,an order’s policies may result in including some imperfect products in arrival lots.A discount on price may be offered by the supplier on the out-of-stock products to manage the backorder problems.The study aims to develop a model with imperfect products by permitting the price discount in backorders,and the cost of ordering is considered a decision variable.First,it is assumed that the demand for lead time is followed by a normal distribution and then stops it and assumed that the first two moments of demand for lead time are known.Further,the minimax distribution method is used to solve this model,and a separate algorithm is designed.In this study,two models are discussed with and without a normally distributed rate of demand.The current study verified with the help of some numerical examples over various model parameters.

Inventory models for deteriorating items with fixed lifetime, partial backordering and carbon emissions policies

In this study,a sustainable inventory model is devised to obtain the retailer’s optimal pricing and replenishment policies for degrading items having a certain lifetime incorporating partial back order as a shortage and dynamic demand under two different scenarios(a)carbon cap and trade policy(b)carbon tax policy.The primary objective of this study is to maximize the retailer’s annual total profit.The retailer’s profit function has been optimized with the help of convexity/concavity criteria employing classical optimization techniques.Based on a real case study,two different numerical examples and corresponding optimal solutions have been shown for both models with the help of Lingo 17 software.Moreover,the impact of the major inventory parameters and prominent managerial insights are presented for the robustness of the proposed model that can cooperate with industrial managers/decision-makers for the overall improvement of his/her industry to take effective and qualitative decisions.

A Petri Net Pareto ISO 31000 Workflow Process Decision Making Approach for Supply Chain Risk Trigger Inventory Decisions in Government Organizations

The Petri Net Pareto method proposed in this study has the advantages of acting directly on computing results by assessment of workflow process information. Our study contributes to the literature because it has investigated an ISO 31000 workflow process approach to group decision making for reducing backorders in the supply chain, from an integrated perspective utilizing Pareto charts and Petri nets. The contribution to the literature is also enhanced by the L-Project illustrative example that presents an evaluation hierarchy of supply chain risk. The proposed method is appropriate for use in situations in which assessment information may be qualitative or precise quantitative information is either unavailable or too costly to compute.

An inventory analysis in a multi-echelon supply chain system under asymmetry fuzzy demand:a fmincon optimization

In this article,the three-echelon supply chain model is developed with a single supplier,a single vendor and a single buyer in a fuzzy environment.The threestage inspection technique is considered at the end of the vendor’s process to supply high-quality products to the buyer.Moreover,the demand rate of the product in the market is often assumed to be uncertain,and accordingly,in this paper,the uncertainty is handled using fuzzy numbers.The primary goal of this model is to minimize the overall inventory cost relative to the asymmetry hexagonal fuzzy demand.Additionally,a backorder strategy is incorporated to gain customer satisfaction and reduce lost sales.To validate this model,numerical examples are tested and constrained non-linear optimization(i.e.fmincon solver)is performed to derive the optimal solution for the decision variables.Finally,conclusions with potential future directions are provided.

Optimal Policies of an Inventory System with Multiple Demand Classes

This paper deals with a periodic review inventory system serving multiple demand classes that are differentiated by the treatment for shortages.Shortages of some classes were treated according to lost-sales,while those of the others were backlogged.In each period,both replenishment decisions of inventory and allocation for all classes were made by a setup cost for each replenishment.By using the approach of stochastic dynamic programming formulation,the optimal replenishment policy is a state-dependent（s,S） policy,and the optimal allocation decision follows a state-dependent prioritization policy.

Multi-Echelon Inventory Model with Emergency Lateral Transshipments

In multi-echelon inventory systems, since neighboring retailers are located at shorter distances than the supplier, a retailer may seek stock from them when it is out of stock, that is, emergency lateral transshipments between retailers are commonly practiced to provide improved order fill rate. In this paper, we develop a continuous review multi-echelon model for consumable products when emergency lateral transshipments between retailers are allowed. Approximations are derived for the expected level of cost and order fill rate of retailers. Simulations conducted to test the validity of the approximate analytical model indi-cate that it performs very well in the cases where fairly high service levels are required. Numerical examples are also presented to illustrate the effects of emergency lateral transshipments on the performance criteria of inventory systems. The results indicate that emergency lateral transshipments will lead to a significant in-crease in the retailer order fail rate and this initiative is most suitable for items with a high penalty cost, or where lost sales are likely.

Inventory and sales decisions in a vendor–buyer system with imperfect items and learning in inspection

In this study,we propose a joint economic lot-sizing model to include learning process along with errors in inspection and full backordering system.We aim to study pricing and inventory decisions in a two-level supply chain involving a single vendor and a single buyer in which the demand is sensitive to price and company’s advertisement efforts.The mathematical inventory model is developed analytically and solved using a proposed algorithm.The objective of the model is to maximise joint total profit by simultaneously determining optimal shipment size,number of deliveries,backorder quantity and product selling price.A numerical example is provided to show the application of the model and to investigate the impact of key parameter’s changes on model behaviour.By comparing the integrated/centralised model to the independent/decentralised model,we note that the integrated/centralised model provides better profit to the system,along with lower selling price and smaller amount of backorder.