Tearing is a way of "breaking up" or tearing dependencies in a model formulation. It can be used in equation based (EO) or sequential modeler (SM) environments. The principle is to tear certain dependencies in the model or flowsheet and then attempt to "close" the tear using inner-outer fixed point iterations. The idea is that the inner-outer problem is easier or faster to solve than the original problem, even though several outer iterations may be required to close the tears.