Hi Mohammed,
High Bandwidth utilization happen mostly because of users trying to download or upload for the applications located across WAN link. You can use "ip accounting" or "Netflow" to identify the source using more bandwidth.
Below are few link you can use.
http://www.ciscopress.com/articles/article.asp?p=764234
http://www.cisco.com/c/en/us/td/docs/ios/12_2/switch/configuration/guide/fswtch_c/xcfnfc.html
Once you identify the application which is eating you bandwidth, you can apply QoS and restrict the usage.
Once you have Bandwidth management I expect Jitter and loss will also minimize.
I hope you are talking about memory utilization:
you can use command "show proc memory sorted" to check what all processes eating memory.
Please rate if it helped.
HTH
-Amit