I am developing what I expect the “model year 2012” SCM system should encompass. In a Supply Chain Management system, EDI and ERP are  intrinsically tied together. Therefore, I am planning  to evaluate the SCM SYSTEM, not just the EDI module or the ERP module. Shown below are the selection criteria I would want to be fulfilled. Right now this evaluation is kind of skimpy: sort of need to add to add more salami between the bread. Based on your comments, I may add, subtract or modify these requirements. 

(1) Entire system will be Cloud-based. 

(2) ERP (Enterprise Resource Planning), and CRM (Customer Relationship Management), if included, are SaaS. Expected modules are: manufacturing, logistics, finance and procurement.

(3) EDI is SaaS (Software-as-a-Service).

(4) EDI and ERP interface is “seamless”.

(5) Trading Partner interface can be Cloud-based, using an ECCP (Electronic Commerce Communications Provider). Adding trading partners should be done “underprogram control”.

(6) For “Legacy” Trading Partners, there must be a VAN (Value Added Network) interface. The current externally configured VAN structure (big solutions, long contracts) is better implemented as a Web Services API (Application Programming Interface).  In other words, no FAX's to VANs to establish relationships.