Creating groups of Windows Computers that are running an application, and their Health Service Watcher objects

This is a really good article from Tao Yang, that incorporates several blog examples on creating groups, and puts them into an extremely common real world scenario.  I find more and more customers needing to understand this very basic level of XML authoring to be successful with SCOM:

http://blog.tyang.org/2015/01/18/creating-opsmgr-instance-group-computers-running-application-health-service-watchers/