Application consolidation: There are fundamental limits to scale, because of the inevitable feature creep, process conflicts, and data complexities.
Non-ERP's: Although the illustrated building blocks are labelled "ERP," other environments such as portals reach diminishing returns
Cross-boundary: Clearly, two companies are unlikely to share the same ERP, so it is with respect to eBusiness in which the issue crops up most dramatically
Synchronized worldviews: needed to leverage across boundaries the capabilities and content of "monolithic" applications
Interface architecture: One can chose across a range of tiny-purpose to general purpose interfaces.
Interface functionality: reads are fairly simple - e.g., most are just queries, but writes involve more complexity.
Bypass level: it is often advantageous to use available APIs. However, application suppliers may create barriers
Finished goods?: It may be cumbersome to have the source application interface produce fit-for-purpose results, so post-processing may be helpful
Access control/security: again, often better addressed with pre and post-processing than conventionally