There are actually a bunch of very good articles written up on IT Toolbox - specifically under the ERP Selection list.
The best article really explains that moving from one ERP to another is not going to make any issues "go away" - most issues with implementing ERP systems revolve about how the system has been implemented - not necessarily the software itself. If the selection criteria for an ERP system is adequately met by one type of software - why look elsewhere for another, just to have to go through an entire implementation all over again ?
You're running a pretty old version of Oneworld - although it is certainly stable - and you're in the position where you can start looking at the next 5-10 years strategic direction. If you are completely dissatisfied with how Oracle and JDE has worked for you up until now, then your only option is to investigate SAP. However, you really should weigh up the decision whether to upgrade or not, since upgrading from Xe to, say, 8.12 should be a lot less expensive than a completely new rollout.
If the software you currently have does not meet the needs of your organization - then you made the wrong choice. However, if your organization has spent the last 7 years trying to make the software look like some other bespoke application - then moving from JDE to SAP isn't going to help you at all.
I've seen companies move from JDE to SAP - and I've seen companies move from SAP to JDE - they all have their reasons, and sometimes those reasons are valid and sometimes they're emotional.
