Hi Poluskinha,
Don't know what the System Analysis you're mentioning is but as for analysing a data center I would recommend you to have a greater look at a data centers electrical efficiency. Fire management, security, accessability, redundancy, et cetera are all customized to reach your customers expectations, while your electrical efficiency is something you attain for your own sake.
Electrical efficiency can be measured by your data centers total electricity consumption devided by IT load power.
Example: a data center consisting of only one 200W server have a total 400W power consumption. This because of UPS, cooling, lightning, ventilation, et cetera.
The example above has a crappy electricity efficiency, 400/200 = 2.
I recommend you to write a lot about how you can achieve good electric efficiency, both for economic reasons as for environmental reasons.
For your question about whether you should build a data center underground I say it's just a matter of your customers needs.
I've always build our data centers at ground level or a few floors up. Easier and cheaper installations of cooling, electrical, ventilation and fire extinguish system. Haven't yet had a customer that demands an underground data center but I bet it's cheaper and better synergy redundancy effect that you have 2 data centers at different locations then to build one underground.
You can find a lot of information in White Pages, to get you started. Look here for example:
APC - Product Information