Final answer:
The question pertains to retraining protocols in a medical or pharmaceutical setting, but without a specific reference, a definitive number of required tests cannot be provided.
Step-by-step explanation:
The question seems to be related to the protocols followed in medical or pharmaceutical environments, specifically concerning the retraining of personnel who have failed critical assessments like written tests or practical observations. However, without specific reference to a regulatory body or standard operating procedure, it's not possible to provide a definitive answer to how many successive tests must be passed after retraining. In practice, this number might vary depending on the institution's policies or the regulations of the governing health authority.
In many procedures, quality, and safety protocols, especially within industries like pharmaceuticals, it often requires that individuals demonstrate a consistent ability to perform their duties reliably and correctly, but the exact number of required successful tests can be set by internal policies or based on external regulations.