Last time buy and repair decisions for spare parts

Original Equipment Manufacturers (OEM’s) of advanced capital goods often offer service contracts for system support to their customers, for which spare parts are needed. Due to technological changes, suppliers of spare parts may stop production at some point in time. As a reaction to that decision, an OEM may place a so-called Last Time Buy (LTB) order to cover demand for spare parts during the remaining service period, which may last for many years. The fact that there might be other alternative sources of supply in the next periods\ud complicates the decision on the LTB. In this paper, we develop a heuristic method to find the near- optimal LTB quantity in presence of an imperfect repair option of the failed parts that can be returned from the field. Comparison of our method to simulation shows high approximation accuracy. Numerical experiments reveal that repair is an excellent option as\ud alternative sourcing, even if it is more expensive than buying a new part, because of postponement of the repair decisions. In addition, we show the impact of other key parameters on costs and LTB quantity

Last Time Buy and repair decisions for fast moving parts

Spare part availability is essential for advanced capital goods with a long service period. Sourcing becomes challenging once the production of spare parts ceases, while the remaining service period is still long. In this paper, we focus on fast moving parts with repair of failed parts as an alternative supply option. We proceed from the methodology of Behfard et al. (2015) for slow movers, which assumes discrete demand distributions and therefore leads to excessive computation times for fast movers. We find that the use of continuous demand distributions requires significant modifications, both for the approximation of the performance indicators and for the optimization of the repair policy. We develop accurate heuristics to find the near-optimal Last Time Buy (LTB) quantity and the repair policy that we apply for two control policies: pull return - push repair, and push return - pull repair. We show that pull return - push repair is better to follow if return lead times are short and return costs are low. For long return lead times, we find that when the return cost exceeds 35%–40% of the part's value, push return - pull repair becomes more cost efficient. We also show that for relatively high demand of spare parts over the planning period (>300 for a 10 years planning period) the continuous model is a good approximation for the discrete model of Behfard et al. (2015). In addition, the computation time of our method is much lower then

Last time buy and repair decisions for spare parts

Original Equipment Manufacturers (OEM's) of advanced capital goods often offer service contracts for system support to their customers, for which spare parts are needed. Due to technological changes, suppliers of spare parts may stop production at some point in time. As a reaction to that decision, an OEM may place a so-called Last Time Buy (LTB) order to cover demand for spare parts during the remaining service period, which may last for many years. The fact that there might be other alternative sources of supply in the next periods complicates the decision on the LTB. In this paper, we develop a heuristic method to find the near-optimal LTB quantity in presence of an imperfect repair option of the failed parts that can be returned from the field. Comparison of our method to simulation shows high approximation accuracy. Numerical experiments reveal that repair is an excellent option as alternative sourcing, even if it is more expensive than buying a new part, because of the option to postpone the repair until the parts are needed. In addition, we show the impact of other key parameters on costs and LTB quantity

Der Faktor Unsicherheit bei ersatzteillogistischen Kooperationen auf dem Drittanbietermarkt

Die zunehmende Ersatzteilvielfalt bedingt durch kürzer werdende Innovationszyklen bei gleichzeitig langanhaltender Lebensdauer komplexer Anlagen und der Trend der Auslagerung von Dienstleistungen bewirken, dass der Drittanbietermarkt in der Ersatzteillogistik an Bedeutung gewinnt. Strategisch ausgerichtete Kooperationen zwischen Herstellern, Drittanbietern und Betreibern sind wichtig, um planungsintensive Prozesse nachhaltig zu optimieren. Unsicherheiten behindern jedoch die Bereitschaft, Allianzen einzugehen und sich gegenüber Innovationen in diesem Bereich zu öffnen. Durch eine qualitativ ausgerichtete Studie mit Akteuren des Drittanbietermarktes wurden die Relevanz aus der Literatur erarbeiteter Kooperationsmöglichkeiten erfasst und bestehende Unsicherheiten bzw. deren Ursache erforscht. Die Unsicherheit bezüglich verlässlicher Informationen erwies sich hier als zentraler Aspekt