Abstract: A computer-implemented method and system for simulating a program modeled as one or more blocks of a block diagram in a computing environment. The one or more blocks having at least one signal, the computing environment including a model editor, a data definition tool and a code generator. The method includes: Simulating the block diagram for a first time span in the simulation environment, Displaying the values of the signal as a function of the simulation time, Receiving a pause command at a specific simulation time and a new value for the parameter, Simulating the block diagram for a second time span in the simulation environment, and Displaying both the values of the signal from the first time span and the values of the signal from the second time span. The values from the second time span are displayed graphically different from those of the first time span.