services depend on services

[] to list the services on the computer that have dependent services

PS R:\> get-service | where-object {$_.DependentServices}

Status Name DisplayName
------ ---- -----------
Running dmserver Logical Disk Manager
Running EventSystem COM+ Event System
Stopped lanmanserver Server

[] to display the complete list of dependent services of MSSQLSERVER service

PS R:\> (get-service mssqlserver).dependentservices

Status Name DisplayName
------ ---- -----------
Stopped SQLServerAgent SQLServerAgent

[] to display the number of dependent services that each service has

PS> get-service | where-object {$_.DependentServices} | format-list -property Name, DependentServices, @{Label="NoOfDependentServices"; Expression={$_.dependentservices.count}}

Name : lanmanworkstation
DependentServices : {RpcLocator, Netlogon, Messenger, Browser...}
NoOfDependentServices : 5