Hi C.G.Unnikrishnan,
In my humble opinion, it would be much fortunate to open your issue as a separate thread instead of as a sub-thread under Robson's original one.
Your issue, question requires a long-long answer because its generality, so can not answer you, just briefly.
We are the Business Partner of JDE in Hungary and we have 10+ OneWorld customers. Yes, we have a bunch of customization as well as client specific as our country specific. Yes, we have a bunch of job to retrofit these customizations after ESUs and Updates but we have no other choice. How to hard to retrofit a customization is vary. Generally add-ons rarely requires any modifications. Mods on original JDE object is an other issue. The time requirement and complication to retrorofit these mods depends very much on its type (control, eventrule, BSVW extensions, etc.) and its complications.
Should I advise to you to open your issue in an indpendent new thread but please, narrow your issue a bit. I am sure, you will get more answers that time because almost all of us on this forum have a bunch of customizations.
Regards,
Zoltán
P.S.: do you mean "300 locations" as 300 workstation or something else?
B7332 SP11, ESU 4116422, Intel NT4, SQL 7 SP1
(working with B7321, B7331, XE too)