I find this to be very handy when we have a situation where we require troubleshooting in terms of performance as you can see exactly what was running when, how much memory/cpu utilization etc.
To start the collection run transaction /n/SDF/MON or go to SA38 and execute job /SDF/MON.
Click on SCHEDULE NEW MONITORING
Fill in the desired parameters like the duration of the analysis and the interval for the snapshot and execute
Once this is done go back to /SDF/MON and click on EXECUTE
Double click on the line to access the MONITORING DATA page.
On this page you can double click on the DIA/CPU/FREE MEM etc. to get and overview of what was running on the system at that exact time.
Hope this is helpful
Any feedback would be appreciated