Thanks for your answer. The data are in file geodatabase. Below is the code that I use in Python window in ArcMap. I am not sure but I will check which version of Service pack I have.
Best regards,
Suzana
>>> import arcpy
>>> from arcpy import env
>>> env.referenceScale = "50000"
...
>>> arcpy.ResolveBuildingConflicts_cartography("smallpol_point_Rep","visibility","'Road_merge_Rep1' 'true' '0 meters'","30 meters","30 meters", "")