How to get Parent Item while creating child item

  Hi Experts, I have custom ItemType called "GR Projects" which is a parent Item. and Document is Child Item. My Scenario: I want dynamic activity assignment for the document when the document is added to the "GR Projects". but the dynamic activity assignment depends on the name of "GR Projects" Item which is Parent. I start the document workflow on "OnAfterAdd" on Document Server Method and at the same time I want to do the dynamic assignments for document depend on "GR Projects" Parent name, but the link is not created between "GR Projects" and Documents until I save the "GR Projects" Item. I tried this: (OnAfterAdd of Document)

Dim inno as Innovator = getInnovator()

Dim docItem as Item = Me.newItem("Document","get")

Dim docNumber as String = Me.getProperty("item_number")

Dim AML_to_getProjectName as String = "<AML>"+
 "<Item type='GRIL Project Document' action='get' select='source_id'>" +
 "<related_id>" +
 "<Item type='Document' action='get'>" +
 "<item_number>"+ docNumber +"</item_number>" +
 "</Item>" +
 "</related_id>" +
 "<source_id>"+
 "<Item type='GRIL Project' action='get' select='_project_name,item_number'></Item>" +
 "</source_id>" +
 "</Item>" +
 "</AML>"
Dim ResultProjectName as Item = inno.applyAML(AML_to_getProjectName) 
CCO.Utilities.WriteDebug("ResultProjectName",ResultProjectName.ToString())
 
below is the error I get in ResultProjectName file.

<SOAP-ENV:Envelope xmlns:SOAP-ENV="">schemas.xmlsoap.org/.../"><SOAP-ENV:Body><SOAP-ENV:Fault xmlns:af="">www.aras.com/.../faultcode><faultstring><![CDATA[No items of type GRIL Project Document found.]]></faultstring><detail><af:legacy_detail><![CDATA[No items of type GRIL Project Document found.]]></af:legacy_detail><af:legacy_faultstring><![CDATA[No items of type 'GRIL Project Document' found using the criteria: <Item type="GRIL Project Document" action="get" select="source_id"><related_id><Item type="Document" action="get"><item_number /></Item></related_id><source_id><Item type="GRIL Project" action="get" select="_project_name,item_number" /></source_id></Item> ]]></af:legacy_faultstring></detail></SOAP-ENV:Fault></SOAP-ENV:Body></SOAP-ENV:Envelope>   How should I get the Parent Item Object at the time of creation of child Item, is there any method/event