According to the model, the critical driver of fundamental change is upheaval in the environment of the institutions.In particular, the punctuated equilibrium theory of organizational evolution posits that two forces provide the impetus for change in institutions, that is, for punctuating a reorientation that disrupts a period of convergence: "(1) sustained low performance and (2) major changes in competitive, technological, socail, and legal conditions in the environment"that make existing arrangements increasingly ineffective. Tushman and Romanelli maintain that shocķ from the environment can be addressed either through anticipatory actions or skilled work after impact, and that the internal dimensions of the organization can be brought into congruence with external forces.