Hi @walgram, you can specify a log file path in the command line with an option argument called LOG_FILENAME. e.g.

"C:\Program Files\FME\fme.exe" "C:\workspaces\myworkspace.fmw" --SourceDataset "C:\source\data.ext" --DestDataset "C:\output" LOG_FILENAME "C:\log\test.log"

Alternatively, you can create a user parameter linking to the Log File parameter in the Navigator window and then specify your desired log file path in the command line through the parameter.

, this is another way to define a logfile name dynamically, using python:

You can of course use any other system parameter rather than "FME_MF_NAME". Or any other python function rather tham "time".

With the given settings, every fme run produces a new logfile.