EPM 2007 provides "Project Server Gateway" for mapping the data between Portfolio Server 2007 and Project Server 2007.
One of the common query that I have noticed is 'why attribute from project server is not gettign listed for mapping?.
Well key lies in the type mapping followed by the gateway:
Custom fields are mapped based on their type following the above table:
PS project custom field types
PPS attribute types
Text
String
Text with lookup table
List
Text with lookup table + “Allow multiple values to be selected from lookup table” option checked
Multiple Text
Cost, Cost with Lookup Table
Number, Number with Lookup Table
Number
Date, Date with Lookup Table
Date
Note:
Export to PS or import from PS deletes existing value and updates it with the new one.
This is why for PPS attributes mapped on Lookup Table custom fields, if the value that has to be updated doesn’t exist on the Lookup Table or List instances, the result will be Blank
Thats the reason it is always a best practice i have learnt through my experience to leave all the fields blank (in PPS) while you export project (which means all the fields in the attribute mapping template will have option selected as None from the dropdown).
Once the export is successfull edit the data in Project server for the fields mapped with PPS and perform a refresh on portfolio wherein all the values get back mapped onto portfolio from Project server.