Debugging Performance related issues.

There is no hard and fast rule for any trouble shooting. However, you may follow below guidelines to troubleshoot the perfornace related issues in your environment.
It requires debugging the following and in the specified order:
1. Database server
2. Application Server
3. WebServer
4. Network Bandwidth
5. PeopleSoft Application code itself
6. Memory of the boxes where the Appserver/Webserver booted.
7. Browser related
Step 1. Take multiple Database instances say PROD and TEST and try to execute SQL commits through front-end GUI, PIA. Observe the time complexities between the statements. The time taken should be relatively the same if there is any significant difference you know where the problem lies!
Step 2. Application Server tuning requires to set a lot of parameters in the PSAPPSERV.cfg file .
Check the follwing Parameters :
What is the size of the domain? small, medium, large ?
How many services booted for PSAPPSRV, PSQRYSRV, PSQUICKSRV ?Is there any core dump? Where does it fail? Get the error message from Appserv.log and the TUXLOG ?
Are the users power users or end users? If power users what kind of queries, reports and code do they kick off? Get an idea by actually reviewing those panels/pages and accordingly boot the required services in the Appserver. Use correct spawn values and TIMEOUTS. Check for any garbage collection. After trying all these try to boot the Appserver again with reset values and check the performance.
Verify the communication between the Appserver and the Database server.
Step 3. First thing I would recommend is to quickly boot an alternate webserver on a different box, installing PIA on top of it and point to the same Appserver to see if it still an issue. If the page gets a decent performance then you know the issue lies with that particular Weblogic install, get rid of it as it waste of time debugging it. Have the users point the URL to the correct install
Step 4. Load a third party application and compare it's performance wrt to PSFT.
Step 5. If 4 does not resolve anything then it could be bad Apps code which is causing this. Use Peoplecode debugger and debug the code.
Step 6. Make sure that there is decent swap size memory UNIX/NT/2000. On windows you turn on the task manager to see if there is a memory leak and/OR sudden spike in CPU usage. On UNIX you can increase the kernel parameters and increase the swap size to see if it makes any difference .
Step 7. There is not much you can do here other than how the performance is wrt IE vs Netscape etc. Most of these end up as PeopleTools product issue reports.
For RAS in users make sure the compression is always set to true in the configuration.properties