The thesis talks about the project I have been carrying out during my last four months of internship within ATR Aircraft, a company that manufactures and produces aircrafts of medium range (around 50 seats per aircraft). In particular, the project speaks about the amelioration of a process already consolidated in the company, which involves the Change Advisory Board. This board meets once every two weeks to discuss of potential enhancements that could be implemented in order to improve the product. When these improvements are done though, there is no way to monitor the creation of the cost for what concerns the spare parts of the new configuration.