KLM Engineering & Maintenance Component Services manages a spare part pool. They are responsible for ensuring spare part availability for their contracted customers. For rotable spare parts, which are interchangeable and repairable, the supply chain is closed-loop. As the demand for spare parts is sporadic, with large zero demand periods, a loan service is introduced for non-contracted customers in order to increase the spare part utilisation rate and gain additional revenue. This research evaluates potential strategic options to increase the contribution of the loan desk to the performance of KLM Component Services. It is important that the effect on the availability service for contracted customers is limited. Gaining control over the availability decision regarding non-contracted customers was considered as top priority. It was found that the risk-based availability decision could result in a revenue increase of 24% of the loan service, yet enables management to control the effect on the availability service regarding contracted customers.