How to solve compare drawing problem in CAD software?

[Virini]

I have a problem in mechnical CAD drawing....I'm in position of design and drawing drafts by CAD, but my colleague always change my drafts.
What's worse, I cannot figure what have they done!
I know that many people have confronted with the same problem. Can someone give me any suggestions?

[Hashwu]

Well, poor people! Recently, I've found a piece of news from CE introducing a drawing tool of CAD to compare the differences between two DWG files after design modifications. Maybe you can find some useful information from: GstarCAD 2011 Releases New Function – Drawing Compare - CrazyEngineers
If you work with many collaborative engineers, you can quickly figure out your own draft.
Hope more people who know it well give more explanations...
Good luck for you!