Inventory Model For Perishable Items Research Articles

An Inventory Model for Perishable Items with Cubic Deterioration Rate Having Shelf-Life Price, Stock, and Time-Dependent Demand Rate

An Inventory Model for Perishable Items with Cubic Deterioration Rate Having Shelf-Life Price, Stock, and Time-Dependent Demand Rate

Warehouse Inventory Model for Perishable Items with Hybrid Demand and Trade Credit Policy

Warehouse Inventory Model for Perishable Items with Hybrid Demand and Trade Credit Policy

Inventory model for perishable items for interval-valued price dependent demand and advance payment policy with parametric approach via particle swarm optimization

ABSTRACT Advance payment for replenishment and the lifetime of an item are the most vital issues in the business sector. With the consideration of these issues, the formulation of a non-deterministic inventory model in the interval environment is of great importance. In this work, two different non-deterministic inventory models are formulated along with a variable holding cost, variable demand, and advertisement frequency under an advance payment policy in the interval environment. In the first inventory model, a no-shortage situation is discussed, whereas in the second model, a stock-out scenario is adopted by partially backordering during modelling. The modelling framework for both problems is accomplished based on interval differential equations. The interval optimization problems related to both models are obtained utilizing parametric approach and interval mathematics. Then, using interval order relations and different types of quantum particle swarm optimization, both interval optimization problems are solved. By means of two examples, the authentication of both models is examined and the benefits of the proposed approach are demonstrated. The impact of deviations of various parameters on optimality is studied graphically through the performance of sensitivity analyses, and the work is concluded by providing potential management insights and future scopes.

Multi-echelon supply chain inventory model for perishable items with fuzzy deterioration rate and imperfect production with two-warehouse under inflationary environment

Multi-echelon supply chain inventory model for perishable items with fuzzy deterioration rate and imperfect production with two-warehouse under inflationary environment

Inventory model for perishable items for ramp type demand with an assumption of preservative technology and Weibull deterioration

Inventory model for perishable items for ramp type demand with an assumption of preservative technology and Weibull deterioration

Multi echelon fuzzy inventory model for perishable items in a supply chain with imperfect production and exponential demand rate

Multi echelon fuzzy inventory model for perishable items in a supply chain with imperfect production and exponential demand rate

Multi-echelon supply chain inventory model for perishable items with fuzzy deterioration rate and imperfect production with two-warehouse under inflationary environment

Multi-echelon supply chain inventory model for perishable items with fuzzy deterioration rate and imperfect production with two-warehouse under inflationary environment

Analysis and optimisation of periodic inventory models for perishable items with a general lifetime

We considered two periodic review perishable inventory systems. The first system is controlled by a periodic review policy, where orders are triggered at each review period and when the stock is less than . The second one is controlled by a periodic review policy, where orders are triggered only if the stock level is below . For both models, the lifetime of each product was assumed to follow a general distribution, whereas the lead time was constant. The demands followed a Poisson process, and all unsatisfied demand was lost. Using an approximate solution of the steady-state probabilities of the inventory level, we obtained a closed form of cost expression. Next, we conducted a simulation study to identify our solution accuracy. Finally, we performed a sensitivity analysis to evaluate the effect of the lifetime variation and cost parameters on the best policy and its cost. The obtained results were close to those of the optimal policy with an average accuracy of 3.7% for the periodic review policy and 3.8% for the periodic review policy. For the worst cases, where the accuracy is higher than 7%, we provided an analytical approach to improve the system accuracy.

Performance measures of nonstationary inventory models for perishable products under the EWA policy

Accurately estimating key performance indicators in inventory models for perishable items is essential in order to assess and improve the management strategy of these systems. We analyse the production of platelet concentrates at blood banks under the EWA replenishment policy. We give analytical approximations of the most important performance measures, such as the size of orders, the size of stocks, the percentage of outdating, the age distribution of stocks and the freshness of units issued, among others. The production of platelet concentrates is a prototypical example of inventory models for short life items with random demand and a weekly pattern, where a high service level is required. The methodology and the approximations presented here can be easily adapted to other inventory systems with similar characteristics. Most of the formulae in this article are new for nonstationary models under the EWA policy; indeed, formulae for the age distribution of units in stock and of units issued have not appeared in the literature even for the simpler base-stock replenishment policy. We apply our results to a real blood bank and find very close agreement between the formulae and the results of Monte Carlo simulations. The accuracy of our approximations is also tested in several scenarios, depending on the lifetime of units, safety stock levels and the probabilistic distribution of demand.

Interval valued demand and prepayment-based inventory model for perishable items via parametric approach of interval and meta-heuristic algorithms

This work mainly focuses on the mathematical formulation of an imprecise inventory model with partial prepayment policy in interval environment. In the proposed model, two different cases (without shortage and with partially backlogged shortages) are taken into consideration. Here, the demand and deterioration rates are considered as interval valued. Also, all the inventory costs, viz. ordering cost, purchase cost, holding cost, shortage cost and lost sale cost are considered as interval valued. Then, the continuous change of inventory level with time of the proposed model is defined mathematically by the interval differential equations. For both cases of the proposed model, the interval valued average profits are obtained by using parametric approach of interval. Here, the selling price and business period are taken as decision variables of the corresponding interval maximization problem. Finally, two numerical examples are considered and solved by using different meta-heuristic algorithms for checking the validity of the proposed model.

Inventory Model for Perishable items for Ramp type demand with an assumption of Preservative technology and Weibull deterioration

Inventory Model for Perishable items for Ramp type demand with an assumption of Preservative technology and Weibull deterioration

Controllable carbon emissions in an inventory model for perishable items under trade credit policy for credit-risk customers

The incorporation of credit risk and environmental regulations has been attended to considerably in the literature of inventory models; however, papers rarely developed a model considering both of these issues concurrently. Thus, jointly incorporate these two challenges makes sense to address the mentioned gap in the literature and outline insights for future works in practice. This study develops an inventory model for deteriorating items which (a) items deteriorate continuously and have their specific expiration dates; (b) carbon is emitted due to ordering and warehousing operations when a cap-and-tax policy is regulated and emissions can be controlled by investing in green technology; (c) two levels of trade credit is offered when the customer must pay a prepayment. The purpose of this study is to compare the retailer's total profit for different values of upstream and downstream trade credit periods to achieve efficient pricing and replenishment decisions. An algorithm is developed to find the optimal value for the investment in green technology. Numerical experiments and sensitivity analysis are elaborated to validate the mathematical formulation. Finally, findings are summarized and managerial implications are addressed.

A Fuzzy type Backlogging Production Inventory Model for Perishable Items with Time Dependent Exponential Demand Rate

Production inventory models have an important role in production planning and scheduling. In any economic production quantity (EPQ) model, the production rate is dependent on demand. In this paper we have established a production inventory model for perishable items with partial backlogging and time dependent exponential demand rate. Allowing shortage, it is partially backlogged. The unsatisfied demand is backlogged and it is considered a function of waiting time. The aim of our study is to optimizing the total profit during a given cycle. A numerical example is given in showing the applicability of the developed model.

An Inventory Model for Perishable Items with Price-, Stock-, and Time-Dependent Demand Rate considering Shelf-Life and Nonlinear Holding Costs

Nowadays, consumers are more health conscious than before, and their demand of fresh items has intensely increased. In this context, an effective and efficient inventory management of the perishable items is needed in order to avoid the relevant losses due to their deterioration. Furthermore, the demand of products is influenced by several factors such as price, stock, and freshness state, among others. Hence, this research work develops an inventory model for perishable items, constrained by both physical and freshness condition degradations. The demand for perishable items is a multivariate function of price, current stock quantity, and freshness condition. Specific to price, six different price-dependent demand functions are used: linear, isoelastic, exponential, logit, logarithmic, and polynomial. By working with perishable items that eventually deteriorate, this inventory model also takes into consideration the expiration date, a salvage value, and the cost of deterioration. In addition, the holding cost is modelled as a quadratic function of time. The proposed inventory model jointly determines the optimal price, the replenishment cycle time, and the order quantity, which together result in maximum total profit per unit of time. The inventory model has a wide application since it can be implemented in several fields such as food goods (milk, vegetables, and meat), organisms, and ornamental flowers, among others. Some numerical examples are presented to illustrate the use of the inventory model. The results show that increasing the value of the shelf-life results in an increment in price, inventory cycle time, quantity ordered, and profits that are generated for all price demand functions. Finally, a sensitivity analysis is performed, and several managerial insights are provided.

Partially backlogging inventory model for perishable items with reliability and price varying demand

Reliability is an important factor of any inventory system for attracting the customers towards its products. Mostly highly reliable products are preferred by the customers in the real/super market. Assuming, reliability any business organization can reduce their total cost or total profit. The proposed paper deals partially backlogging inventory model for perishable items with reliability and price varying demand. The shortages are partially backlogged. The unsatisfied demand is backlogged and governed by a function of waiting time. The objective of the study is to optimizing the total cost and selling price during a given period of time. The validity of the proposed model is shown by a numerical example along with the behavior of key parameters.

Multi echelon fuzzy inventory model for perishable items in a supply chain with imperfect production and exponential demand rate

Multi echelon fuzzy inventory model for perishable items in a supply chain with imperfect production and exponential demand rate

A Two Warehouse Inventory Model for Perishable Items with Ramp Type Demand and Partial Backlogging

A Two Warehouse Inventory Model for Perishable Items with Ramp Type Demand and Partial Backlogging

Inventory models for perishable items with advanced payment, linearly time-dependent holding cost and demand dependent on advertisement and selling price

Advertisement is one of the most effective ways to spread out the popularity of the product for all categories of customers. Consequently, this has a direct impact to aggrandize product's demand to a great extent. On the other hand, if the maximum lifetime of a product is expired once then it can neither be useable nor be re-useable. Thus the date of maximum life time of the product is an essential issue in inventory management. Advance payment is another important factor among interrelation of suppliers and retailers for a highly demanding seasonal product. Combining these issues, two different inventory models for perishable items are formulated under linearly time-dependent increasing holding cost whereas demand of the product is dependent on the selling price of the product and the frequency of advertisement as well. In the first model, shortages are not considered whereas in the second one, partial backlogged shortages are incorporated. In both cases, the optimality of the proposed inventory models is discussed theoretically along with its solution algorithm. To validate the proposed models, three numerical examples are solved. Finally, the effect of changes of different parameters is studied numerically to perform a sensitivity analysis and a fruitful conclusion is done.

Continuous review (s, Q) inventory system with random lifetime and two demand classes

This paper examines a continuous review inventory model for perishable items with two demand classes. Demands for both classes occur according to Poisson process. The items in inventory are perishable products and have exponential lifetimes. The time after placing an order is an exponential random variable. When the on-hand inventory drops to pre-specified level s, only the priority customer demands are met whereas the demands from ordinary customers are lost. And also, the demand occurring stock-out periods are lost. The inventory system is characterized by continuous-time Markov process and steady-state probabilities are derived. The expected cost function is formulated and a numerical study is provided for optimization.

An optimal inventory model for perishable items under successive price discounts with permissible delay in payments

This article derives an optimal ordering policy for non-instantaneously deteriorating items under successive price discounts with delay in payments. Here successive price discounts is a strategy to sell almost all the items before decomposition. The cause of implementing this concept in the model is the fact that about 25% of vegetables and fruits of India gets decayed before selling, due to lack of facilities and awareness of business strategies, although poverty is its vital factor. Thus we propose to offer successive price discounts of 20% and 40% after selling the stock up to 50% and 90% respectively to raise the customer’s inflow and so also rotate the cycle early to avoid more deterioration. This type of business not only reduces the factory of decomposability but also saves the holding cost partially. In addition to, the delay in payment is another business strategy of the wholesaler by which he keeps the retailers in track and so also reduces the holding cost. In this case the wholesaler offers an interest-free credit period to the retailers till the settlement of the accounts. The retailers earn interest on selling the revenue during this opportunity. Supplier charges interest on the outstanding balance after exceeding the period. Besides the above, again the inventory cost does not remaining constant due to various factors like inflation, salary, house rent etc. so a time varying holding cost has been well thought out instead of constant holding cost. Once more customers’ flow not only depends upon the price instigating but also on timings, hence we assume an exponential demand function which depends on these variables. The main idea of the task is to determine optimal selling price, optimal refill schedule and optimal ordering quantity such that the total profit is maximized under exponential constraints. The literal idea of the work is (a) to avoid the deterioration through successive price discounts, (b) to attract the customers through successive price discounts, (c) to sell all the items through successive price discounts, (d) to rotate the cycle early through successive price discounts, (e) to keep the retailers in track through delay in payment, (f) to keep variable holding cost instead of constant holding cost due to market inflation, (g) to get the optimum results under exponential constraints.