To PI or not to PI
I tend to end up in some interesting discussion, with other consultants, customers and my self. The last part is often a big problem.
I was working with a client, where we had to do and migration. From SAP business connector to SAP Process Integration. One thing that I realized this process is that all the development that we do, have to be changed at some point.
We do not know how long time is the key is going to support its appeal process integration, if there is going to be an upgrade path all the time. Or if our strategy is to move away from the PI system at some point. Therefore, whenever we develop something, it always have to be replaced later. It can be costly to do and migration from one platform to another. The people that did the original of development is no longer in the organization or may not know the new tool.
When we are developing SOA applications we all played saying that it is a great thing to have products developed using the SOA thought. SOA creates an infrastructure that allows a lot of reuse. But what happens down the line when no one knows what we have reusing. Who know what is going on 10 years from now.
One thing that I was considering was direct connections to SAP ERP. If for instance want to connect at portal to the ERP system. Then we have two options for doing this.
- We can connect directly to the SAP system from the portal. The benefit of this is less latency, less development, and an easy-to-understand architecture. The downside it is difficult to know what is going on, who is calling which services. The security is not optimal since it allow direct access to the ERP system from the DMZ.
- We can also connect through SAP PI, and expose the services using the ESR. By doing this we have a better way to secure who gets access to the SAP system, we can close firewall from the Internet. We have more flexibility of what we want to expose. And we have the whole SOA concepts that we can use. The downside is we have to have this system running all the time, and we have to upgraded whenever it’s needed. You are not going to change the SAP ERP system to ORACLE, so you just can change the connections with little effort.
I recorded video around some of the concepts, and thought that I had on direct connections vs thru SAP PI.
I think one important aspect is if we are dealing with web services, we should at least publish these in the ESR. So no matter what we want do we can always see where the services this exposed. We may not get the locking from the PI if we dealing with direct communication but we will get some more flexibility in other respects.
I still believe that using SAP process integration is still good use in some scenarios, way want to expose which services to a portal or a DMZ. We just have to consider some of the downsides of having an integration broker in in between.
Do you have any recommendations regarding connecting direct to ERP system or thru the PI system.