Many to many relationships is a typical requirement in most data base applications. Being able to apply the same concepts to SharePoint lists and document meta data is simply not possible with the OOB SharePoint. By using QWS SharePoint designers can build applications based on multiple lists of master data [this data can exist in SharePoint or in external solutions] with 'many to many' data relationships. The data relationship models can be built up and defined for use in any application. Master data can be linked to related child lists and updates to master data can be automatically refreshed at the child item level.