The influence of spare parts provisioning on buffer size in a production system

ABSTRACT

We consider a discrete-part production line consisting of two machines with random processing and failure times. One option that can mitigate the effect of these uncertainties is the installation of a buffer between the two machines to avoid starving and blocking of the machines. In this article, we additionally allow the keeping of spare parts in stock to enable a fast repair and reduce machine downtime.

 We introduce a new model to support the optimization of the buffer size and the spare parts inventory level simultaneously. The model is based on a continuous-time Markov chain and our aim is to minimize the average costs, which are composed of costs for work in process and the stock-keeping of spare parts, subject to a minimum target throughput.

 Our numerical analysis reveals that the availability of spare parts can increase throughput enormously or reduce the required buffer size for a given target throughput. Using our approach, as opposed to a sequential approach, we can quantify the cost savings, which can be obtained by a joint optimization of the buffer size and the inventory level. Large cost savings can be obtained by the application of our new approach.

KEYWORDS:

• Manufacturing systems modeling
• Markov chains
• buffer
• spare parts inventory
• unreliable machines

Additional information

Notes on contributors

Gudrun P. Kiesmüller

Gudrun P. Kiesmüller holds the chair of operations management at the Otto-von-Guericke University in Magdeburg (Germany). She obtained her Ph.D. in mathematics from the Julius-Maximilans University in Würzburg (Germany) and was working as a postdoc and an assistant professor at the Technical University Eindhoven (The Netherlands) before she was affiliated as a professor for supply chain management at the Christian Albrechts Universität zu Kiel (Germany). Her main research interests are related to stochastic modeling in after-sales service, inventory control, and supply chain management.

Julia Zimmermann

Julia Zimmermann is a Ph.D. candidate at the chair of operations management at the Otto-von-Guericke University in Magdeburg, Germany. Her current research topic is the design of manufacturing systems with spare parts provisioning.