This article aims to conceptualize the manufacture of outpatient services in a level 3 entity of the health sector, under a Lean Healthcare approach. For the development of the proposed objective, it was necessary to characterize the system from the analysis of waiting lines due to the variable and non-deterministic behavior commonly observed in service systems. The phases of the characterization are composed of a general description of the processes that make up the outpatient service, followed by an economic-operational diagnosis, where productivity measurement was used with a value-added approach (MPVA) and a questionnaire to evaluate compliance with criteria of the Lean philosophy. Using the Kolmogorov-Smirnov test, probability functions are determined and from this the process of outpatient care is conceptually proposed.