There are probably too many questions packed into this thing, but if you have time, would love to hear some varying thoughts and opinions. 

Back story:

I'm trying to do a cost transparency build, and am approaching IT Resource Towers (ITRT). I have created financial cost objects and will be allocating from vendors, time tracking, labor, and fixed assets (also potentially other cost pools object). My intention was to build ITRT before building out Services. However, I am struggling with how to include the details that will be useful for allocating to Services later. I thought that I could worry about Service details after completing the ITRT layer, but the more I read the more it seems like I need to know what Services look like before I send costs to ITRT.

So I’m curious about a few things:

• How have you added granularity to your ITRT? 
• Is it possible to construct ITRT without knowing the construction of Services?
• If I need to add Service level detail prior to ITRT, how do I avoid cluttering my ITRT to the point of poor performance? (Also what’s the point of towers, if I can’t make them without services?)
• I see in the reference project there are Vendor and Application and Project and Application associations mapped to ITRT Master Data - also this conveniently comes from ACME's general ledger. Have any of you built this in without Application information in your general ledger? How and when (before or after ITRT)? 

Anyway, back to adding granularity

• Do you use metadata columns and keys? 
• Has anybody created a really neat one column code to pack up details prior to and unpack after ITRT?

I'm not looking for best case scenario examples, I'm interesting in outside-the-box - "I'm making an organizations round peg fit into an Apptio square hole"- answers. Thanks for you time - lets see how this goes!

i don't know how much "out-of-the-box" these answers are, but here we go:

1. Yes, we have metadata to identify where the costs should go. Apart from the IT infrastructure, also to Applications. Exceptionally, to Business Services.
2. Is it possible to construct ITRT without knowing the construction of Services? Yes. We had just one exception to point one above: one of our business services is the result of an acquisition and the associated costs go in bulk from ITRTs to business services.
3. We do not add anything about services, except what I detail in 1 & 2.
4. We do not have Application information in our GL, we enrich line items depending on our configuration tables.
5.  Do you use metadata columns and keys? Yes, see 1 above.
6. Has anybody created a really neat one column code to pack up details prior to and unpack after ITRT? No. We find "neat", compact solutions very hard to troubleshoot further down the line. It's already difficult enough as it is.

P.S. We cannot link Projects to the IT infrastructure given the data we have, so one less issue to worry about. The price: incomplete project cost information.

@Guillermo Cuadrado - thanks for the feedback! I was thinking the same thing about number 6 - might be cool, but would probably just complicate things. Anyway, glad to hear about the rest concerning apps and ITRT.