A method of saving portions of a simulation or execution engine image at various points in a simulation or execution is disclosed. The saving of the simulation or execution context in addition to the more traditional saving of the system state information enables the restoration of a simulation or execution that is capable of producing, in a subsequent simulation or execution of a block diagram continuing from the point of the saved simulation or execution, results that are identical to those of the initial simulation or execution. The ability to restore more than just system state variables enables a user to run multiple variations of a simulation from a given point without having to replicate the simulation up until the point of the saved initial simulation, and the ability to run multiple iterations of a block diagram execution in a non-simulation execution from a given point without having to replicate the execution of the block diagram up until that point.