1. Portal-Server program ( 1 ) comprising means to add Dynamic Nodes to an existing typology tree, means to identify Dynamic Nodes in typology trees and to invoke a Dynamic Assembly module for processing said Dynamic Nodes, an Adapter ( 20 ) which provides means to create a topology fragment, and a Dynamic Assembly Module ( 16 ) which provides means to call said Adapter ( 20 ), to validate a topology fragment provided by said Adapter, and to merge said topology fragment with said existing typology tree at run time.