Set a project parameter for a project deployed to SSISDB

I am using PowerShell to deploy a project to SSISDB and to set a project parameter. (This is loosely based on this article : http://blogs.msdn.com/b/mattm/archive/2011/11/17/ssis-and-powershell-in-sql-server-2012.aspx )

The script creates a folder, and successfully deploys the project from the isPac file. The package in the project runs successfully from SSMS Integration Services Catalog node.

I am attempting to change the value of a project parameter. It appears that the parameter gets changed, but that the change is not persisted to SSISDB.

The following script illustrates the problem I am having.

Run the script: .\TestPPrm (within PowerShell) - this displays the before/after parameter values

Run the script again as: .TestPPrm 1 - this only displays the parameter value, which show the original value.

The project itself contains a package with a script task that simply displays a variable using FireInformation(). The project has a project parameter named PParm2, defined as a string with arbitrary content.

Script:

param ([boolean] $show = 0)
"-- show $show"
$global:cat = 0
#-------------------------------------------
function AccessCtlg {
 # Load the IntegrationServices Assembly           
 $loadStatus = [Reflection.Assembly]::Load("Microsoft"+           
 ".SqlServer.Management.IntegrationServices" +           
 ", Version=11.0.0.0, Culture=neutral" +           
 ", PublicKeyToken=89845dcd8080cc91")           

 # Store the IntegrationServices Assembly namespace to avoid typing it every time           
 $global:ISNamespace = "Microsoft.SqlServer.Management.IntegrationServices"           
 Write-Host "Connecting to server ..." -f cyan

 # Create a connection to the server           
 $global:constr = "Data Source=localhost;Initial Catalog=master;Integrated Security=SSPI;"           
 $global:con = New-Object System.Data.SqlClient.SqlConnection $constr

 # Create the Integration Services object           
 $global:ssis = New-Object $ISNamespace".IntegrationServices" $con

 # Get the catalog reference
  if ($global:ssis.Catalogs.Count -gt 0)            
 {            
  Write-Host "Opening SSISDB Catalog ..." -f cyan
  $global:cat = $global:ssis.Catalogs["SSISDB"]
 }           
 else
 {           
  Write-Host "SSISDB Catalog does not exist ..." -f red
 }
}
#------------------------------------------------------
function ShowPPrm ($p, $when) {
 $n = $p.Name
 Write-Host "Parameter: $n ($when)" -f green
 if($p.DefaultValue.length) {
  $v = $p.DefaultValue
 } else {
  $v = $p.DesignDefaultValue
 }
 $t = $p.DataType
 Write-Host @"
 Value : $v
 DataType: $t
"@ -f darkgreen
}
#-------------------------------------------------------
# Set project parameters
function SetPrjPrms($project, $parm, $value) {
 Write-Host "Setting project parameters ..." -f cyan
 $lit = [Microsoft.SqlServer.Management.IntegrationServices.ParameterInfo+ParameterValueType]::Literal
 $xp = $project.Parameters[$parm]
 ShowPPrm $xp "Before"
 $xp.Set($lit, $value)
 ShowPPrm $xp "After"
}
#------------- Main ------------
AccessCtlg               # Open SSISDB

$project = $cat.Folders['Example'].Projects['DeployTest']   # Get the project reference

if($show) {
 $xp = $project.Parameters["PParm2"]
 ShowPPrm $xp "*"
} else {
 SetPrjPrms $project "PParm2" "The quick brown fox."    # Set the project parameters
}