If your company is not using a monitoring product but as WAS
administrator you have to tune the application server behaviour (in a
simple way), IBM Support Assistant can help you a lot with one of his
Following the technote instructions if you are using IBM JVM 1.5 SR10 or above, you can enable one or more application server on WAS to use Health Center just copying some files and adding this generic argument (-Xhealthcenter).
After that you can connect to the application server using ISA and monitoring the JVM behaviour at runtime.
For example verifying how the garbage collector is working or if your heap is too small for the applications running on the application server.
Just a couple of suggestions: you'll need to grow up the ISA heap size modifying the file
C:\Documents and Settings\Administrator\IBM\ISAv41\.config\rcpinstall.properties
changing the parameter
And it's better to redirect the log file to a known location using the parameter