ABSTRACT
The act of medical biology is part of a diagnostic, preventive, prognostic and therapeutic approach. The quest for quality must therefore be the essential and constant concern of the biologist and laboratory personnel. This work studied the applicability of Standard 15189 to the parasitological examination of stool, a qualitative method highly dependent on the human factor in addition to technical expertise, a mastery of the working environment and documentation which is essential for the proper execution of the analyzes. The methodology used is a combination of organizational and technical arrangements to master the critical points. A risk analysis and failure modes were carried out in order to detect and prioritize the critical elements to be mastered and to design preventive actions. The results of this ADR have led us to pay attention to the pre-analytical phase, the correct performance of which determines the quality of the analysis; and the analytical phase, the mastery that depends on the competence and empowerment of staff and the accuracy of technical procedures