Load Test Webservice on SoapUI

Hi,

I have been using SoapUI for a while now however this is my first time using load testing in SoapUI. Recently we have been seeing timed out issue in one of our webservice and wanted to find out
if it has anything to do with high traffic use. I tried to test the load on webservice through load testing on SoapUI. This is what i did (correct me if i did something wrong):
1) Created new testcase
2) Added new 'Contatins' assertion in addition to 'Soap Response' to see if the return value was equal to expected value.
3) Added load test and ran the test under these settings:
a) ThreadsL:5, Strategy: Threads, Start Threads: 1, End Threads: 5, Limit: 60 Seconds
b) ThreadsL:10, Strategy: Threads, Start Threads: 1, End Threads: 10, Limit: 60 Seconds
c) ThreadsL:15, Strategy: Threads, Start Threads: 1, End Threads: 15, Limit: 60 Seconds

During my testing the service errored out most of the time.
So, is it right to assume that the webservice doesn't function well when there is high traffic?
P.S: I have also attached the screenshot of my soapUI project.

Thanks.
Sanjeev