Thesis defense of Erwin van Wingerden, January 24, 2019

On Thursday, January 24, 2019, Erwin van Wingerden will defend his PhD thesis “System-focused spare parts management for capital goods”. This thesis has been supervised by G.J.J.A.N. van Houtum and dr. T. Tan. The ceremony will take place in the Collegezaal 4 of the Auditorium Building at the Eindhoven University of Technology at 16:00 hrs.


When a capital good, such as the lithography machine of ASML, used in a 24 hour production process is out of order for a period of time, this has a big impact on the entire production process and will cost the production company a large amount of money. A proper management of the maintenance of capital goods is important to make sure downtime of these capital goods is kept to a minimum. Capital goods generally consist of many different critical parts which cause the machine to stop working when a part has broken down. In case this happens, it is generally not easy nor the fastest option to repair the broken part on site, and therefore the part is preferably replaced by a spare part to bring the capital good back up and running as fast as possible. However, simply stocking an ample amount of stock is also not desirable as this results in high holding costs as parts can be very expensive. Therefore, one generally prefers to have the highest availability of capital goods while at the same time minimizing the inventory holding costs of spare parts. In the thesis, we focus on developing models with this aim in mind. We first consider models that are applicable for the initial phase of a capital good, where many new spare parts are introduced, there is a lot of uncertainty on the failure rate of these parts, and companies can choose to invest in more reliable failure rate information. Next, we consider models for the stationary phase of a capital good where there is less uncertainty and the focus is on complex service networks with the possibility of emergency shipments, as well as providing a framework to make system-focused spare parts inventory control easier applicable in practice.