Hi:
Lets say that I need to implement something - anything - that can add together two single-digit numbers. Now there are a wide variety of mechanisms I could use to perform this addition. I could:
* Write a software program
* Create an electronic device
* Create a mechanical device
* Hire a person whose only task is to do it.
* Train a dog to do it (yes, this is possible, I saw such recently on TV).
Granted some of the above mechanisms are not very practical. But my point is that functions is functions, irregardless of the mechanism used to accomplish them. To model my solution - irregardless of the mechanism I choose - I would use data flow diagrams. They allow me to create a conceptual (i.e., technology indepedent) model independent of the solution.
I have used DFDs on serveral occasions to functionally model systems whose main mechanism is electronics. When I went throught data flow diagramming training, they taught us that DFD's could be used to model how a car functions. But this is a little hard for me to envision.
Tony