Doctoral Thesis Advances in Inventory Management Dynamic Models

Defended on Thursday, 24 June 2010

Abstract

In this study, we develop and analyze models incorporating some of the dynamic aspects of inventory systems. In particular, we focus on two major themes to be analyzed separately: nonstationarity in demand rate and unfixed purchasing prices.

In the first part of the study, we consider an inventory system with a nonstationary demand rate. In particular, we consider critical service parts subject to obsolescence. Inventory management of such items is notoriously difficult due to their slow moving character and the high risks involved when they are not available or no more needed.

In practice, there is a need for policies tailored for service parts taking these aspects into account and easy to implement. We propose an obsolescence based control policy and investigate its performance and impact on costs. We find that ignoring obsolescence in the control policy increases costs significantly and early adaptation of base stock levels can lead to important savings.

In the second part of the study, we consider an inventory system where the supplier offers price discounts at random points in time. We extend the literature by assuming a more general backordering structure. That is, when the system is out of stock, an arriving customer either decides to be backlogged with a certain probability or leaves the system and becomes a lost sale.  We derive equations to calculate optimal policy parameters and demonstrate that allowing backorders in face of random deal offerings can result in considerable savings.

Keywords

inventory management, nonstationary demand, obsolescence, service parts, base stock policy, advance policy change, excess stock, installed base, random deal offerings, price discounts, partial backorders

Time frame

2005 - 2009

Preferred reference

C. Pinçe, Advances in Inventory Management: Dynamic Models, Promotor:Prof. dr. ir. Rommert Dekker, http://hdl.handle.net/1765/19867

Author

Cerag Pince
Cerag Pince

Supervisory Team

Rommert Dekker
Professor of Econometrics (Operations Research and Informatics)
  • Promotor
Hans Frenk
Hans Frenk
  • Copromotor

Committee Members

Roelof Kuik
Roelof Kuik
Associate Professor in Quantitative Methods in Supply Chain Management
Rob Zuidwijk
Endowed Professor of Ports in Global Networks