First of all, for debugging purposes, redirect the stderr to some file as well. This way you'll know what goes wrong.
15 * * * * /bin/ksh /wls_domains/resMGT/logs/bea/wlr3queuetransaction.sh 2>LOG_FILE > /wls_domains/resMGT/logs/bea/data/script.log
Next if it isn't a file location issue, take a look at this question, as it is very similar: how to set crontab PATH variablehow to set crontab PATH variable.