The present invention provides methods and systems for using a design element in a graphical model to represent and identify a precondition for use by a verification tool in verifying an executable form of the design represented by the graphical model. The precondition design element provides a specification of a verification constraint without affecting the behavior of the design. The constraint is to be applied by the verification tool in verifying the design. As such, the precondition design element of the present invention provides a mechanism and formalism in a model-based design approach that is used to constrain automatically generated tests or verification of the design represented by the graphical model.