looks great. Conditionally loading a config. Might be able to make it more resilient by making sure what you think is there, like "/inc/script/my_lib.conf". You are checking $ENV{PAR_TEMP} to see if it's set, but not checking to see if it's set correctly. Is the file there? Does it have all the data you need? Does it bomb out correctly when somethings wrong? Assume that something will go wrong, now how long is it going to take to find out why with the default error messages?
Break it imaginatively and just kinda see what happens.