How to sanction without causing pain?

In the humanitarian sector, dedicated to alleviating people’s suffering, how to qualify a misconduct and impose a potentially painful sanction? How can one judge, i.e. consider that everyone is responsible for their act, in a working area based on the fact that human inequalities are partly due to social determinisms? To what extent tolerating deviance is exacerbated and sentences are attenuated if not lifted? Where do the limits of the acceptable stop?