Robots and autonomous system have become a part of our everyday life, therefore guaranteeing their safety is a crucial issue. Among the possible methods for guaranteeing safety, monitoring is widely used, but few methods exist to generate safety rules to implement such monitors. Particularly, building safety monitors that do not constrain excessively the system's ability to perform its tasks is necessary as those systems operate with few human interventions. We propose in this paper a method to take into account the system's desired tasks in the specification of strategies for monitors and apply it to a case study. We show that we can synthesize a more important number of strategies and we facilitate the reasoning about the trade-off between safety and function-alities.