In the automotive world, warranty costs have a significant impact on the overall expenses incurred by manufactures. Furthermore, during the last years, they have undergone a significant increase due to several factors, in particular for the electrification of vehicles. For these reasons, understanding how to reduce them is crucial for increasing the profitability and the efficiency of carmakers. So, this Master’s Degree thesis has as main aim the study of the warranty costs in the automotive world: after an analysis of a real case, the factors influencing these types of expenses have been explored in depth. This study derives from an internship done in Accenture, during which a project for an important carmaker has been followed.