We show the optimality of state dependent echelon base stock policies in uncapacitated serial inventory systems with Markov modulated demand and Markov modulated stochastic leadtimes in the absence of order crossing. Our results cover finite time horizon problems as well as infinite time horizon formulations, with either a discounted or an average cost criterion. We employ a novel approach, bas...

Inventory is lifeblood in an organization. Multiechelon inventory of Olympia paper mill, Khyber Pakhtonkhwa is optimized by efficient management of the organizational supply chain (SC). A supply chain is designed starting from raw material receiving from supplier up to finished good delivered to the customer. The on-going setup of the selected organization is traditional based on the experience...

Inventory control is a crucial activity for many companies. Given the recent advances in information technology, there have never been greater opportunities for coordinated inventory control across supply chain facilities. But how do we design efficient control methods and policies that take advantage of the detailed information that is now becoming available? This doctoral thesis investigates ...

Previous researchers have developed ways of managing forward-oriented supply chains, and gave insight to solve single-stage inventory systems. In this study, we analyze an inventory system with traditional forward-oriented material flow as well as a reverse material flow supply chain. In the reverse material flow, the used products are returned, remanufactured and shipped to the retailer for re...

We present a continuous-review inventory model for tactical planning in a multi-item, multi-echelon service parts distribution system with time-based service level requirements. Our goal is to determine base stock levels for all items at all locations so that the service level agreements are met at minimum investment. We present exact time-based fill rate expressions for each item and efficient...

e establish lower bounds on the minimum costs of managing certain productiondistribution networks with setup costs at all stages and stochastic demands. These networks include serial, assembly, and one-warehouse multi-retailer systems. We obtain the bounds through novel cost-allocation schemes. We evaluate the bounds' performance for one-warehouse multi-retailer systems by comparing them with s...

Globalization, product proliferation and fast product innovation have significantly increased the complexities of supply chains in many industries. One of the most important advancements of supply chain management in recent years is the development of models and methodologies for controlling inventory in general supply networks under uncertainty, and their wide-spread applications to industry. ...

We consider inventory control in a two-echelon divergent network, consisting of a central depot and multiple (non-identical) local warehouses. Past research has shown that (R, S) order-up-to control rules for this system type can easily be obtained using a decomposition approach, where the derivation of the order-up-to level S is separated from the derivation of the rationing parameters. We sho...

Stochastic inventory control in multi-echelon systems poses hard problems in optimisation under uncertainty. Stochastic programming can solve small instances optimally, and approximately solve large instances via scenario reduction techniques, but it cannot handle arbitrary nonlinear constraints or other nonstandard features. Simulation optimisation is an alternative approach that has recently ...

Globalization, product proliferation, and fast product innovation have significantly increased the complexities of supply chains in many industries. One of the most important advancements of supply chain management in recent years is the development of models and methodologies for controlling inventory in general supply networks under uncertainty and their widefspread applications to industry. ...