in this study, a new stochastic model is proposed to deal with a multi-product, multi-period, multi-stage, multi-site production and transportation supply chain planning problem under demand uncertainty. a two-stage stochastic linear programming approach is used to maximize the expected profit. decisions such as the production amount, the inventory level of finished and semi-finished product, t...

This paper proposed a new general probabilistic multi-item, single-source inventory model with varying mixture shortage cost under two restrictions. One of them is on the expected varying backorder cost and the other is on the expected varying lost sales cost. This model is formulated to analyze how the firm can deduce the optimal order quantity and the optimal reorder point for each item to re...

This paper illustrates the relationship between quality improvement, reorder point, and lead time, as affected by backorder rate, in an imperfect production process. To reduce the total system cost by optimizing the setup cost, lot size, lead time, reorder point, and process quality parameter simultaneously, we first consider that the lead time demand follows a normal distribution, then we appl...

An inventory management system for defective items with backordered shortages is explored, in which we assume that the quality of an ordered lot is not always 100% perfect, so a screening process to each product is conducted to split that lot into perfect and defective products. Meanwhile, the defective products include imperfect and scrap ones, which will be sold at a discount price and dispos...

Huang [ Journal of Statistics and Management Systems, Vol. 6 (2003), No. 2, pp. 171-180 ] studied the EOQ (Economic Order Quantity) and EPQ (Economic Production Quantity) models with backlogging and defective items using the algebraic approach. He assumed 100% inspection policy and the known proportion of defective items was removed prior to storage or use after the screening process. In this p...

This paper studies the multi-item stochastic capacitated lot-sizing problem with stationary demand to minimise set-up, holding, and backorder costs. is a common in industry, concerning both inventory management production planning. We study applicability of Proximal Policy Optimisation (PPO) algorithm this problem, which type Deep Reinforcement Learning (DRL). The modelled as Markov Decision Pr...

The bullwhip effect, a well known phenomenon occurring in business activity where the demand information is not fully shared among the members of supply chain, conducts the upstream manufacturer to excessively anticipate the demand capacity of the downstream retailer. The manufacturer improperly decides the amount of the products not only to raise the inventory cost on the way of poorly handlin...

We consider a distribution system with a central warehouse and multiple retailers. The warehouse orders from an outside supplier and replenishes the retailers which in turn satisfy customer demand. The retailers are nonidentical, and their demand processes are independent compound Poisson. There are economies of scale in inventory replenishment, which is controlled by an echelon-stock, batch-tr...