EDI - great idea but ...
At my last job I was responsible for the EDI that some of our customers insisted on using. It was "sort of" integrated into our main systems, but only for limited documents. Trouble was, to do it "properly" would have cost a fortune as the system vendor knew how to screw customers on module costs.
The biggest issue though is that the EDI standards had too much flexibility. It's not enough to say "yes, we can invoice electronically", we (or rather the people who managed our EDI package for us) would have to configure all the foibles that each customer wanted.
But then several large customers insisted on stuff that we just couldn't do. The result was that at various times we had separate and stand alone EDI packages for individual customers - and because these were for one customer, it wasn't worth the cost of trying to do any integration.
EDI saved the customer lots of cash because ... the supplier did all the admin work for them. Orders were still rekeyed, but that was invisible to the customer. Invoices were still manually produced in the EDI package, but that was invisible to the customer. Big customer got all the benefit, small supplier got nothing but extra costs.
In many cases there was no fundamental reason for them not accepting a "standard" invoice, but because "they've always done it that way", some customers simply wouldn't - and didn't care because they never saw the costs of the consequences. As small suppliers we had a simple choice - accept it or not deal with them.
AFAICS, all this XML stuff is just EDI with a different name and set of formats. Unless businesses are prepared to be sensible then it'll have all the same problems as EDI and be no better.
And don't get me started on one large and very well known high street name that insisted we had a face-face meeting. No options, no talk on the phone first - you deal with us, you come to this meeting. So three of use (one for invoicing, one for order handling, one for EDI) had a very long day out to travel to the other end of the country for this meeting - and when it was my turn the conversation was :
> Do you already do EDI ?
> What formats ?
< Tradacoms V9
> Yes, that's OK.
A whole f***ing 18 hour day for two questions - but they didn't care as it wasn't a cost to them ! Needless to say, if I'd spoken my mind we wouldn't have been selling to them.
And after all that, they'd still screw you on prices, and when you couldn't go any lower they'd dump you anyway. But we mustn't forget, every little helps ... their bottom line, not yours.