slow AIX system

Hello, is there any way for me to find out why my AIX system is so slow? I’ve tried running VMSTAT and IOSTAT but I’m not sure what I should look for? I’m getting a lot of calls from external users about this sluggishness and sometimes they get kicked off from their telnet sessions.

My output from VMSTAT is:
kthr: r=0, b=0
memory: avm=51713, fre=374
page: re=0, pi=0, po=0, fr=1, sr=7, cy=0
faults: in=185, sy=612, cs=96
cpu: us=5, sy=2, id=90, wa=3

for iostat:

tin=13.7
tout=1538.5
avg-cpu: %user=4.6, %sys=2.3, %idle=89.8, %iowait=3.3

any suggestions would be appreciated…