simulation

Acting out or mimicking an actual or probable real life condition, event, 
or situation to find a cause of a past occurrence (such as an accident), 
or to forecast future effects (outcomes) of assumed circumstances or factors. 

A simulation may be performed through 

(1) solving a set of equations (a mathematical model),

(2) constructing a physical (scale) model,

(3) staged rehearsal, 

(4) game (such as wargames), or a computer graphics model (such as an animated flowchart). 

Whereas simulations are very useful tools that allow experimentation without exposure to risk, 
they are gross simplifications of the reality because they include only a few of the real-world factors, 
and are only as good as their underlying assumptions. 

mimicking ability
物まねの才能、〔鳥などの〕物まねの能力、擬態

How in the world did you ever conceive of the idea to make a living by mimicking?
一体どうして物まねで生計を立てようなんて思い付いたんだ？

whereas
～であるのに対して［反して］、～である一方で、～だがところが

I hate shopping, whereas my wife loves it.
私は買い物が大嫌いですが、その一方で、妻は買い物が大好きです。

He is talkative and funny, whereas his father, by contrast, is solemn and quiet.
彼はおしゃべりで陽気だが、彼の父親は対照的に物静かで無口です。