We propose a set of recommendations and practices to optimize the use of quality control of medical biology examinations. The fundamentals are reviewed: definition of a series of analysis, IQC at one or more level, Westgard alert rules and rejection, practical remedial actions to take for the technician, corrective and preventive actions to be implemented by the biologist. We have also formalized three flowcharts to guide the technician in their daily practice to ensure analytical quality of investigations carried out. These decision trees are the result of the experience submitted by an accredited and professional laboratory attentive to the ongoing improvement of IQC. This article can provide useful assistance to biologists for accreditation but also aims to foster collaboration reliable medical biology laboratory at the appropriate management of patients.