Spare Parts inventory reduction: a multi-attribute approach

The paper aims to define a multi-attribute model allowing to re-design spare parts (SPs) inventory. The model helps in evaluating the inventory configuration compliant with both production and storage costs requirements. The model is based on SPs attributes to be considered critical for a production system. For each SP a reduction index is computed as a function of the attributes values expressed by the judgments of different decision-makers. A transform function is defined to convert reduction indexes into SPs stock reduction quantities. The transform function is consistent with a set of reduction policies to be adopted on the base of internal (i.e. system utilization) and external (i.e. supply quality) variables affecting system behaviour. The model has been tested and validated on a catalogue of a SPs supplier of an automotive components company. Due to the crisis of the automotive sector of the last two years, the management of the plant shifted the focus from high technical availability level of production system to the reduction of production costs and SPs stock in the local warehouse. Data collection and data mining required for SPs inventory reduction by traditional management policy revealed as time and resource consuming task. Results obtained by the proposed approach revealed the effectiveness of the model in reducing SPs inventory, as well as a reduced effort in carrying out the analysis.