## 2 Literature Review
### Advanced Technologies for Aftersales and Warranty Management  
Digital transformation has revolutionized warranty management, enabling a more predictive and efficient approach that reduces costs and improves customer experience. To achieve this shift, the integration of advanced technologies such as artificial intelligence, the Internet of Things (IoT), digital twins, and blockchain has proven to be instrumental. Each of these technologies is explored below, detailing their specific application in warranty management and their contribution to a more effective and adaptable aftersales service model. Artificial intelligence (AI) is a key pillar in the modernization of warranty management, enabling accurate failure prediction and the optimization of maintenance policies through real-time data analysis. Machine learning (ML) algorithms collect and analyze operational data from assets to identify patterns that could signal future problems before they arise. For example, in the automotive industry, ML systems can continuously analyze vehicle performance and detect wear patterns in specific components, such as the brakes or the engine. This anticipatory ability not only reduces downtime, but allows companies to adjust warranty policies to the actual usage conditions of each asset, thereby personalizing aftersales services [2]. AI, therefore, brings a proactive approach to warranty management, transforming reactive service into a preventive and optimized one. This approach not only benefits the company by reducing costs, but also increases customer satisfaction by offering a fast response tailored to their specific needs [7]. The Internet of Things (IoT) has transformed the way assets are monitored in industry, enabling the use of connected sensors that provide real-time data on the status and performance of equipment and components [8]. These sensors installed on assets make it possible to detect operating anomalies early, facilitating preventive maintenance planning and reducing the need for corrective interventions. In sectors such as heavy machinery, IoT is particularly useful for monitoring the wear of critical parts, such as excavator chains or hydraulic systems. This allows maintenance personnel to proactively intervene before a significant failure occurs, minimizing production interruptions and optimizing resource allocation [9]. By offering an accurate, real-time picture of asset status, IoT improves warranty and maintenance decision-making [10]. In the context of the Fourth Industrial Revolution, IoT thus becomes a key element to optimize the life cycle of assets, as it enables massive data collection and analysis to improve forecasting and long-term performance [11; 12]. In the aeronautical industry, digital twins applied to aircraft turbines allow engineers to simulate multiple operating conditions and assess wear at critical points, anticipating potential failures. This advanced simulation capability not only reduces risks and downtime, but also allows warranty policies to be adjusted based on the actual conditions of use of the asset. As a result, more accurate and customized warranty coverage is offered, aligned with the life cycle and condition of each specific asset [13; 14]. In this way, digital twins become a strategic tool that not only optimizes maintenance, but also adds value to the customer, improving the accuracy of warranty coverage and increasing the reliability and efficiency of assets during their life cycle [11]. Blockchain technology adds an unprecedented level of transparency and security to the traceability of warranty events, from the manufacturing phase to aftersales service. By using blockchain, each maintenance intervention is recorded in an unalterable way, allowing all interested parties to access a common and secure version of warranty information. This traceability reduces disputes and facilitates the resolution of claims, bringing greater confidence and security to the process [15].