On AIX – nmon on AIX can be used to monitoring a machine (CPU, Memory, Network traffic, I/O, top processes, etc). Here is the link to download nmon http://www.ibm.com/developerworks/wikis/display/WikiPtype/nmon

Example to collect nmon data and extract output to a file:
$ nmon_aix53 -fTNWLA -I 0.001 -s 300 -c 288 -m /home/nmon_data
This collects the data once a day in the directory /home/nmon_data at once every 5 minutes and with 288 snapshot which makes a excellent graph detail level. It also collects top processes and user command lines (T), NFS stats (N), Workload Manager but no Subclasses (W), Large page stats (L) and Asynchronous I/O details. The reporting threshold is 0.001 percent of a CPU.

The output from nmon can be graphed using nmon analyzer it reads output from nmon and it can be loaded into excel that graphs to aid in analysis and reports to analyze nmon.
http://www.ibm.com/developerworks/wikis/display/Wikiptype/nmonanalyser