u Information content is different across the process phases
u many flavours of instances (as much as we have process steps?)
u occurance cannot finally be checked by SGML/XML parser
u Different data is generated in different process steps
u sophisticated version control and process management
u tools to merge data
u Not all objects exist along the process chain
u handle broken links
u establish links automatically by knowing the semantics
u convert to standard SGML style for exchange
u Global data models of tools or processes must be mappeded
u export capabilities are determined by the internal data model
u allow multiple global data models
u harmonize data models on SGML level