Thank you very much to all of you for your bright insights... it is very helpful to me and I'm happy to have the confirmation that SD can be used for my particular concern.
@Eric: sorry if I posted the wrong forum - will use your link next time
@Paulo: Obrigado ! Now the concepts are clearer to me, I've understood that what matters is more the mathematical relationships than the words. I will have to work to know precisely how the items from my models fit the SD concepts.
@Warren: your comments were very helpful, I now have a better understanding on how I can get my model started. To get more "dynamicity", I would like to represent the "average user process time to complete" as an additional stock, which depends on the CPU capacity. I have modeled this as you can see in the enclosed picture. According to you, does this make sense? It would be helpful because I would be then able to "plug" new application to this basic model and see the potential impacts on the other applications that are using the same CPU.
Again, thank you very much to all for your precious help, I really appreciate.
Michel
PS : if you're interested on having further discussions about this exciting topic, do not hesitate to contact me on my email.