Belirsiz ömürlü ürünler için belirsiz ve zamana bağlı talep altında en iyi envanter ve fiyatlandırma kararlarının bulunması

In this thesis, we consider inventory management and pricing of perishable products like sheet metals, dairy products, vegetables, pharmaceuticals, fruits, bloods and other related products considering a time-dependent demand function. The main difference that separates perishable products from durable ones is that perishable products have a decreasing demand as they age which leads to being completely obsolete after a certain amount of time. Therefore, both the amount and age of the products are the crucial variables for inventory and pricing decisions which make this decision equations harder to solve. The inventory and pricing decisions problem is a very interesting topic when we look back in the literature; however, these decisions were generally handled separately, and studies that coordinate inventory and pricing decisions were lacking. Most of these studies focused on single product systems with a first-in-first-out structure that assumes the oldest product will be sold to the first customer. Additionally, demand is time independent and not affected by age. However, in reality, customer choices are dependent on the age of the product at hand, because it is rational to say that customers will choose fresher products that lead to a higher demand for new orders, this demand will direct customer interest to fresher products, and older ones will become obsolete. According to this system, first-in-first-out logic may not work, because when a customer has two options to choose between fresher and older products, they will always prefer fresher ones. In this study, we aim to fill gaps in literature by considering the coordinated inventory and pricing decisions in systems where the demand is a function depending on the age of the products at hand. We tried to find an effective way to manage inventory and pricing decisions, which also leads to decreased food waste. This proposed system is important for companies because perishability, unless managed correctly, decreases profit. By considering these facts, we build a model that reflects these real life problems for perishable products and try to find the optimal solution for such systems. When finding the optimal solution is not possible, we build heuristics and find approximate solutions. All in all, we focus on the inventory and pricing decisions by working on a continuously reviewed inventory system with a single type of product and a random lifetime decaying continuously.