The text is concerned with structural changes occurring in complex organizations, an exceptional contingency in the life of organizations, and thus normally passed over as a study subject. Emphasis is placed on a diachronic analysis perspective of the phenomenon of structural changes, by recourse to the image of the life cycle of structures. A model is proposed for the interpretation of the phenomenon that seeks to integrate into a single comprehensive pattern both the actions of authorities that patronize change and the mutation dynamics of people affected by reforms.