When there is a significant gap between user elapsed time and SQL processing elapsed time, and there is PL/SQL code involved, the PL/SQL Profiler
becomes a very useful tool.  It helps to identify the lines of PL/SQL code which are taking longer to process. 

For example, if a transaction which uses PL/SQL Libraries (packages, procedures, functions or triggers) executes in one hour of user elapsed time, and
reviewing the results of the Trace Analyzer (Note 224270.1) or TKPROF only 10 minutes of the elapsed time can be explained with SQL commands being executed, then, by using the PL/SQL Profiler, a line-by-line of the executed PL/SQL application code is reported, including the total execution time for each line of code, and how many times each of these lines was executed.

The guide to use DBMS_PROFILER here gives us a quick idea to implement it. By the way, Oracle Metalink Note: 243755.1 shows how to use include HTML spool file to generate result report.