How to title a report on a project that is not final I thought about posting this in English.SE, but since it occurs in a university setting, I decided to post here - hopefully it's on-topic. 

I have been working on a project that is being transitioned to another group member so she could take over the project. The project involves the design, development, and application of "Model X". I have done some useful work on it, but some work still needs to be done to complete it. I'm putting together a documentation package to describe what I've done so far, the design of "Model X", and how to use the code I've written thus far.

This report is internal to the group (whether this will be part of something that is published in the future, I do not know). I hesitate to title the report "Model X" because it's not, and might not be close to, being the final model. How should I title the transition report?

Some options I have thought of:
"Current status of Model X" - but this seems like an email subject
"Incomplete Model X: Design and Usage" - this sounds a bit degrading

What would you suggest? And are there in fact accepted titles for this kind of report?
I have typically seen the word "Draft" used, as in:


  Draft Model of X (Date)


If you want to track multiple drafts over time, then you can give a version number as well:


  Draft Model of X (Version N, Date)