When we attempt to understand technical things through synthesis, we assemble something that looks and acts like the thing itself-then test the synthetic model. We don't worry about whether the internal mechanisms of the model are anything like those of the real thing, as long as the behaviors match in predictable ways.
Most engineering design is non-deterministic.
That means we do not have a set of equations into which we plug our specifications, and out of which pops an optimal design. Rather, we must iterate through a process of trial and error-build a prototype, try it out until it breaks, make changes, and do it again. We continue in this process until we reach the desired specifications-or until we run out of time or money. It would be nice if we had a tool that could show us something of the behavior of our proposed product at a very early point in the design process. This brings us to GrafiCalc.