Specific Hand Strategy

Has anybody created their own hand strategy for themselves? What I mean is, something like a Word document or an Excel spreadsheet detailing hands and what to do in certain situations, mostly concerning preflop.

For example:

AA

Occurs: 1/220

Action on loose tables

UTG: Raise, reraise
Mid position: Raise, reraise
Late position: Raise, reraise
SB: Raise, reraise
BB: Raise, reraise

Action on tight tables

UTG: Call, reraise
Mid: Call or raise, reraise
Late: Raise, reraise
SB: Raise, call
BB: Raise, call

etc.

If somebody has created something like this, do they find that setting particular actions in stone, knowing what they've theorized is the correct play is written down somewhere, helps their game? Can anybody see any disadvantages to taking such an approach (Aside from the obvious gotta-mix-up-your-play line)?