concurrent active users in SAP System

Hi Friends,

I want to know below information about how to get concurrent active

users in the system.

Information that I have is as below:

SM04 - Active users on one application server

AL08 - Active users on all application servers logged in globally

report - CCUINIT to initialise measurement of concurrent users.

CCUEVAL to get the output of report CCUINIT.

Question is why there is a difference in no. of active users from AL08

(todays highest is 1800 ) & output of CCUEVAL (todays highest is 240)?

Also do we have any mechanism to get no. of concurrent users in the

past?

Please share your expert views.

Thanks.

Best Regards

Sachin Bhatt