As per the following VMware Article Vcops Alerts will be getting refreshed on every 15 mins Interval by default...Inorder to make Alert refreshment in short time (3 mins for testing Purpose), then following file has to be changed on the Analytics VM file level...(Screen Shot - Reference)
File Path --> /usr/lib/vmware-vcops/user/conf/analytics/advanced.properties.
Url --> http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2039020.
Still few case, expecting alerts not reflected timely, does it require to change any more settings for the Alert timing interval on the file/Vcops- Custom console level? 
Please Advice....