Toyota Hellas is undergoing important growth and development. This is reflected also in the after-sales organization where new developments call for continuous improvement of customer service. This project focuses particularly on the results of the after sales activities and consists of developing a (MSI) quality system and plan for its implementation in order to improve the after-sales service (AFS) operations. More specifically, the project comprised an in-depth analysis of existing MSIs, data collection on customers and service activities resulting in the development of an MSI model as a management tool for decision-making. On this basis, proposition of improvement actions to elevate customer satisfaction levels were made.