In the past VMware has had large customers adjust the java heap size for Inventory service, profile-driven storage, and web management. Most commonly it’s the adjustment for Inventory to attempt to improve speed. The patch for U2 and above replaces this setting with default. So you will have to manually after each patch change this setting until you are on vSphere 6 which dynamically adjusts this setting. You can read the VMware article here:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2114669