This is an abstract from the SAP online help.
The transaction code for the workload monitor is ST03N. The workload monitor is used to analyze the statistical data from the R/3 kernel. When analyzing the performance of a system, you should normally start by analyzing the workload statistics. For example, you can display the totals for all instances and compare the performance of individual instances over specific periods of time.
You can use the workload monitor to display the:
1.Number of configured instances for each SAP System
2.Data for all application instances, not just the one you have logged on to
3.Transactions used and the users that call them
4.Number of users working on the different instances
5.Performance history for recent periods for all instances
6.Response time distribution and resource consumption for any application server
7.Application server workload for today or for a recent period.
The new workload monitor ST03N is still being enhanced and has not yet fully replaced the old Transaction ST03.
The workload monitor has a new interface that is divided into two parts. Use the tree structures on the left of the screen to choose the user mode and profiles that you require. The system then displays the results on the right.
The new workload monitor has the following features:
1.Standardized ABAP ALV grid controls, enabling you to search for and filter the information you require.
3.Cross-client information (information on application servers other than the one you have logged on to)
4.Save user-specific views
5.Graphics of the statistics for each task type