Interactive Response Time

I have been asked to come up with a plan so that no user will ever have to wait
more than 30 seconds for an AS/400 interactive response.  The request (from the
company president) was based on a completely out-of-context observation of one
user who had to wait 2 minutes for a response to one particular screen on one
occurrence.  The president's intent is good, he just does not know what he is
asking for.

Because I don't believe his request can be or should be satisfied as he worded
it, I am planning to reshape it into an initiative to monitor both average and
longest response times, set goals (not guarantees) for both, be able to explain
exceptions, and propose a series of solutions that are most cost effective.   I
will report this to him on a monthly basis.  Sounds pretty noble, huh?

Just for the record, Ops Navigator shows that throughout the day our average
response time is normally under 2 seconds, and often under 1 second.  We are
running JDE World on a 730 dual processor.

I am sure there are hundreds of ways to approach this (bigger processor, more
memory, more disks, better management of file sizes, better scheduling of batch
jobs, LPAR(?),  separate test box, programming changes, yada, yada, yada.).

Here is my question (finally).  Other than pulling out the Performance Tuning
manuals, is there a quicker/easier/better way to approach this?  Remember, my
goal is to develop meaningful performance measures and be able to identify
solutions to performance problems.

Thanks.
Phil