Nowadays, the provisions of healthcare are selected for their quality. Hospitals have begun intensely to use one of concept of ISO 9001: "The customer voice", which consists on using the perception of patients to organize their services and improve their global performance. The implementation of Lean Six Sigma (L6S) approach helps to achieve this goal. This approach corresponds to the merger of two quality improvement: Lean and 6 Sigma. Both methods encompass a number of principles and tools designed to increase process efficiency by reducing wasteful steps. This paper presents an application of L6S approach in the hospital sector by focusing on the need to implement this tool to improve the value chain of healthcare, and the KPIs used.