جستجوی مقالات مرتبط با کلیدواژه « Inventory Control » در نشریات گروه « مواد و متالورژی »

This paper presents a three-level supply chain model which includes single supplier, several distribution centers and sets of retailers. For this purpose, by adopting the queuing approach, a mixed nonlinear integer programming model is formulated. The proposed model follows minimizing the total cost of the system by determining: 1) the number and location of distribution centers between candidated ones; 2) the possibility of allocating each of the retailers to the distribution centers; 3) the amount of retailers demand; and 4) the policy of distribution centers. In the proposed model, the cost of waiting in queue is also considered. In order to make the problem more realistic, we consider uncertain demand and lead-time, which follow Poisson and Exponential distributions, respectively. Hence, we apply continuous-time Markov process approach to obtain the amount of annual ordering, purchase and inventory. Then, the results are used to formulate the location-inventory problem. Finally, the proposed model is solved using GAMS software version 24.1.3.

Due to the rapid development of technology in recent years, market competition and customer expectations have increased more than ever. In this situation, it is vital for businesses survival to determine the appropriate policy for inventory control, pricing, and routing, and decisions regarding each of them are often made separately. If the products have a perishable nature, it will be more important to determ ine the above policies. For integration of the decision-making concerning the three key components of the supply chain ,i.e. pricing, routing, and inventory control, two mathematical models were developed for a two-echelon supply chain of perishable items with direct shipment, where fixed lifetime is assumed in one model and random lifetime in another, so that profit is maximized. The proposed mathematical model was solved using the CPLEX solver package of the GAMS software for specification of the optimal policy of the supply chain. The results demonstrated that the CPU time needed for solving the mathematical model for perishable items with random lifetime was less than that for fixed lifetime, while the value of the objective function for products with fixed lifetime was greater than that for products with random lifetime.

Nowadays many well-known firms may produce similar products at different prices in order to remain in the competitive environment. The price differences may cause substitution condition which motivates the customers to substitute similar cheaper product with an expensive one leading to an environment which is known as “customer-based price driven substitution”. This research proposes a new mathematical model towards a joint dynamic pricing and inventory control for seasonal and substitutable goods in a competitive market over a finite time planning horizon. It is assumed that the two substitute goods belong to two different rival firms. The objective is to determine the optimal price, order quantity and the number of periods for one product in the presence of symmetrical and asymmetrical substitutions such that the total profit of the related firm is maximized. First it is showed that total profit is a concave function of price which leads us to a unique optimal solution. To provide the optimal solution a simple algorithm is developed. Finally, in order to evaluate the performance of proposed algorithm a numerical example is presented.