Integrating my RESTful web app with clients' SAP installations

My company runs a couple of B2B apps (written in Rails) dealing with part开发者_Go百科s and inventory and we've been trying to figure out the best way to integrate with some of our bigger users. We already offer the REST-style API that comes with Rails, but that, of course requires an IT Department on their end to decide to integrate it, so we'd like to lower that barrier if possible.

From what we've found, most of them are on SAP systems. Now, pretty much all I know about SAP is it's 1) expensive, 2) huge, 3) and does everything and anything you could ever need for your gigantic business to run. Naturally, this is all a bit imposing, and the resources on the site are a cross between impenetrable buzz-word laden sales material, and impenetrable jargon laden advanced technical material with little for the new, but technically competent user to be able to sink his teeth into.

So what I'm wondering is: as a 3rd party, that's not running a SAP installation, is there a way for us to offer access to our site's data through a web service or other API? Is it just a matter of providing or implementing a certain WSDL (and what would that be)? Is this feasible for someone without in-depth experience with SAP? Or is this a complete non-starter?

I'd say it's not possible without someone who knows the SAP system. You probably won't need to hire someone with in-depth SAP knowledge, but at least for the initial implementation, you'll need both the knowledge and a working system you can develop against. Technically speaking, it's not really that hard, but considering the fact that SAP systems are designed to handle multiple organizations, countries, legal systems, localizations and several thousands of users simultaneously, things are bound to be a bit more complex than almost any other software around - and most of the time not even bloated, it's just easy to get lost in that kind of flexibility.

My recommendation would be to find a customer (or a prospective customer) who has someone in their IT department with the necessary technical and processual knowledge and who is interested in conducting a development project. This way, you'd get access to a real system (testing of course) and someone who can explain to you the basics of the system. But, as I said, be prepared for complexity.

vwegert makes some excellent points.

As to this part of your question:

So what I'm wondering is: as a 3rd party, that's not running a SAP installation, is there a way for us to offer access to our site's data through a web service or other API? Is it just a matter of providing or implementing a certain WSDL (and what would that be)?

Technically it is possible to expose any of your system's services as web-services to a client's SAP system. In order to do this you do not need any prior knowledge of SAP. (SAP should be able to import a WSDL, although there may be some limitations in the earlier pre-ECC5 systems).

For example a service that provides meter reads, airport departure schedules, industry trends etc is not dependend of what is in the user's system or how they set it up. However as soon as there is a need to initiate updates to the client system's data is when you need access to more specialised SAP knowledge.

Also note that many SAP functions can also be exposed as web services, but generally you do need someone with SAP (ABAP) knowledge to do this.

The ABAP language is actually fairly simple, but there is a huge learning curve to understand the data model and the myriad of configurable options in SAP.