Installing Updates from Configuration Manager with PowerShell

If you want to trigger an update available from CM in Software Center via a PowerShell script, you can use something like the following:

$UpdateID = 'Site_1EED8E47-D4D8-4823-883C-4FFE753FA233/SUM_0af47e05-17cb-4756-8610-09ce486df1ba'
$Instance = @(Get-CimInstance -Namespace ROOT\ccm\ClientSDK -ClassName CCM_SoftwareUpdate -Filter "UpdateID like '$UpdateID'")
If ($Instance) {
	Invoke-CimMethod -Namespace ROOT\ccm\ClientSDK -ClassName CCM_SoftwareUpdatesManager -MethodName InstallUpdates -Arguments @{CCMUpdates = [ciminstance[]]$Instance}
}

# And then this to get details on the Progress
start-Sleep -seconds 60
$Instance = @(Get-CimInstance -Namespace ROOT\ccm\ClientSDK -ClassName CCM_SoftwareUpdate -Filter "UpdateID like '$UpdateID'")
write-host "Current Update State: $($Instance.EvaluationState)"
write-host "Current Update Progress: $($Instance.PercentComplete)"

Properties of the CCM_SoftwareUpdate class are laid out here: https://docs.microsoft.com/en-us/mem/configmgr/develop/reference/core/clients/sdk/ccm_softwareupdate-client-wmi-class

EvaluationState property actually has 24 states.  But, most of the time, we'll be interested in only the bolded below.

In State 7, ciJobStateInstalling, the PercentComplete property populates and becomes useful.

In State 13, ciJobStateError, the ErrorCode property (usually) populates and becomes useful.