Changing a rule or process in TM1 does not show up in the logs.
That is fine as long as you are the only Power User able to tinker with these objects.
Unfortunately, it can get out of hand pretty quickly as more power users join the party and make changes that might impact other departments data.
So here goes a simple way to report changes.

The idea is to compare the current files on the production server with a backup from the previous day.

You will need:

• Access to the live TM1 Data Folder
• Access to the last daily backup
• A VB script to email results you can find one there
• diff, egrep and unix2dos
   

Save these files in D:\TM1DATA\BIN for example, or some path accessible to the TM1 server.

In the same folder create a diff.bat file, replace all the TM1DATA paths to your configuration:

@echo off
cd D:\TM1DATA\BIN
del %~1
rem windows file compare fc is just crap, must fallback to the mighty GNU binutils
diff -q "\\liveserver\TM1DATA" "\\backupserver\TM1DATA" | egrep "\.(pro|RUX|xdi|xru|cho)" > %~1
rem make it notepad friendly, i.e. add these horrible useless CR chars at EOL, it's 2oo8 but native windows apps are just as deficient as ever
unix2dos %~1
rem if diff is not empty then email results
if %~z1 GTR 1 sendattach.vbs mailserver 25 from.email to.email "[TM1] daily changes log" " " "D:\TM1DATA\BIN\%~1"

Now you can set a TM1 process with the following line to run diff.bat and schedule it from a chore.

ExecuteCommand('cmd /c D:\TM1DATA\BIN\diff.bat diff.txt',0);

Best is to run the process at close of business, just before creating the backup of the day.

And you should start receiving emails like these:

Files \\liveserver\TM1DATA\Check Dimension CollectionCat.pro and \\backupserver\TM1DATA\Check Dimension CollectionCat.pro differ
Files \\liveserver\TM1DATA\Productivity.RUX and \\backupserver\TM1DATA\Productivity.RUX differ
Only in \\liveserver\TM1DATA: Update Cube Branch Rates.pro

In this case we can see that the rules from the Productivity cube have changed today.