This paper addresses the problem of weak signals management in the domain of industrial safety. We propose a model of the weak signal life cycle, from its emergence to the decision that should be taken to avoid the related hazard. This model represents this life cycle as four successive steps associated with barriers that the weak signal has to overcome. These four steps are: 1. detection; 2. interpretation; 3. transmission; 4. priority setting. For each of these four barriers we discuss human and organisational factors that may support the efficient management of weak signals. In the detection phase, we identify the complementary roles of attention and vigilance. In the interpretation phase, we study the role of mental representations in sensemaking. In the transmission and priority setting phases, we address the concerns of self-confidence and trust in the organisation.