Chapter 10 will be devoted to the process trigger, the initial phase of the system. Shapero’s work provided us with the useful theory of displacement and a model, that of the entrepreneurial event formation. Many years later, I can only commend these works in light of the many cases I have studied, and praise their accuracy and relevance. According to Shapero, the process trigger derives from a factor of displacement, often external, which calls into question the validity of previous choices and positions. Other authors adopted a different point of view and proposed intention models that rely on the intentionality of action and explain the trigger phase through internal dynamics. The theory of planned behaviour (Ajzen 1991) belongs to this second current of research and seems particularly relevant in understanding the process trigger.