Additive or Conventional Manufacturing as spare parts manufacturing technology: the impact of qualification tests

Additive manufacturing (AM) has recently emerged as a potential breakthrough technology in the world of spare parts management. Thanks to its characteristics, it can enable the production of spare parts with very low production lead time, with considerable impacts in terms of inventory levels. Some researchers have recently focused on the topic, trying to understand whether it is convenient to produce spare parts in AM or in Conventional Manufacturing (CM) techniques. However, all these works neglect a crucial aspect. Spare parts, before being utilized, need to be qualified from certified entities. The qualification requirements vary depending on the criticality of the spare parts, but they are all associated with non-negligible costs, which however have been completely neglected so far. In this work, to overcome this gap we develop a mathematical model that can support managers and practitioners in choosing the most convenient manufacturing technology (i.e. AM or CM) considering for the first time the qualification costs. The model proposed has been applied to a real case study to demonstrate its applicability.