Alright I don't mean to sound pedantic but I think this is a good time to give everyone a tip about the English-language rule of compound modifiers: if you have two words that both modify the same noun, and they also precede that noun, you must add a hyphen between them. Forgetting this generally doesn't cause any real confusion, but in some cases really is required for clarification.

In this case, we should write:

`Project-level document for holding analysis data.`

We would not need the hyphenation if the descriptive words followed the noun:

`Documentation on the project level for holding analysis data.`


Further examples are illustrative. Compare:

`The rider fell from his horse, cleaved in twain by the blow from my head-decapitating sword.`
`The rider fell from his horse, cleaved in twain by the blow from my head decapitating sword.`

In the first case, you know that it is my sword that removed his head -- it is a head-decapitating sword, after all. In the second case, it sounds like he was stopped in his tracks by my head, which was also decapitating a sword. All wrong! In this case the example is also redundant, because to decapitate is by definition to cleave off the head, but it helps to illustrate my point.
There are a few other subtleties to this as well but this knowledge alone will get you far in life.