With ST03 we can make workload analysis of our SAP system. There are many aspects of performance and workload analysis in this transaction. But some of them help us to easily make conclusions about system performance. I will write down a few of them .
High Roll Wait Time: This shows you are having problems between your presentation and application layers which means you have to investigate network problems between GUI and application or external RFC connections are slow.
High Load Time: Application server buffers must be loaded from ABAP program ,and the time it takes to load buffer is called Load time. Therefore a high load time can take place because program/CUA/screen buffer is too small ,or there is a CPU bottleneck.
High Roll-In/Roll-Out Time : The time for transferring user context to work processes memory is called roll-in time and vice versa is the roll-out time. And a high roll-in/roll-out time must probably caused from the poorness of SAP roll buffer or SAP extended memory.Another cause can be again CPU bottleneck.
High Processing Time : Processing time directly affected by CPU. Actually processing time must not exceed twice of CPU time. If there is a bigger difference between processing and CPU times , there could be two options.First there could be a CPU bottleneck which make work processes to wait for CPU ,in this case a greater processing time will be caused by CPU wait time .Secondly if the work process stays in STOPPED status ,processing time without CPU time will keep on counting ,so again significant difference between process and CPU time will take place.
High Database Time : If the average database time is greater than 40% of response time minus dispatcher wait time then there is a potential risk of database problem. High database times can be arose from many reasons. Database problems(poor SQL), network problems between database and application servers or CPU bottleneck are the reasons for high database time.