webMethods Upgrade

Hi

I am into a supporting project. We were using SAP BC for B2B and 4.X versions for EAI. Recently we have upgraded the B2B services to IS 6.5.

But still we are keeping the EAI at 4.x. But client is coming up with the query that can we migrate the 4.x stuff into IS 6.5.

I need to do due digilence of the same. Based on my presentation about the migration to IS 6.5 the customer will decide about the migration project.

So i need clear information about the following questions

  1. What are all the advantages of migrating the ES stuff into IS

  2. What the cost impact migrating the Enterprise Stuff to IS?

  3. Why we really need to migrate the ES stuff?

  4. we are having IO, SQL, Oracle, Mail, SAP adapters in ES side. So once we migrate, everything will be running at the IS.

The customer ask us that will it be performance issue?

or will the IS overloaded with all these adapters ??

And what is the advantage of having all these adapters at the same place instead of running in different boxes?

  1. General tips to decide to migrate or not?

It would be very helpful for me if any one can give descriptive answers for the above questions.

I am waiting for your great points…

Thanks in advance