SEMINAR:A discrete time stochastic model of an installed base driven...

Speaker: Hans Frenk, Sabanci University

Title: A discrete time stochastic model of an installed base driven spare parts demand process

Date/Time: Nov 22,  2023, 13:40-14:30

Place: FENS G032

Abstract: Original Equipment Manufacturers aim to design their supply chain before the introduction of their products to maximize after sales business revenues. To this end, they seek long-term projections that captures the main dynamics of products’ life cycles dynamics and spare parts requirements. In this study we introduce discrete time stochastic processes that provide projections for the spare parts demand at any time during the life cycle of the product. In particular, by incorporating the sales process of products, their economic lifetimes, the failure counting process of each product into a single mathematical model, we analyze the size of the installed base, discarded items and returned and defective items stochastic processes over the life cycle of products. We also analyze the stochastic process of the number of returned defective items after any time until the end of the life cycle. As such this last stochastic process is important to determine the size of the last time buy decision which might occur at any time during this life cycle. We focus on determining the expectations, covariance functions and probability mass functions of these stochastic processes at any time for different parametric classes of distributions for the random purchase in any period. This study extends the study by Minner (2011) focusing on a similar model with a deterministic sales process. However, our approach is fundamentally different, which allow us to generalize Minner’s model. This research is in cooperation with Mustafa Hekimoglu (Kadir Has) and Ayda Amniattalab (Sabanci) and is part of the Ph.D thesis of Ayda Amniattalab.

Bio: Hans Frenk joined the Faculty of Engineering and Natural Sciences at Sabanci University in 2009. He graduated from Utrecht University (master degree in mathematics) and did his Ph.D thesis (1984) within the field of renewal theory, regenerative processes and its connection to Banach algebras at the Econometric Institute, Erasmus university, Rotterdam, The Netherlands. Through the years his main research interest is in stochastic processes, optimization and convex and quasiconvex analysis. At the moment his research is in applications of those techniques to problems in Management Science and Engineering. (maintenance, inventory control revenue management and spare parts control). He published both in theoretical and applied oriented journals.