Migration from a dual stack SAP PI to a single stack SAP PI/PO system is a big task.
Many organization is at the moment is in the process of migrating It is away to stay agile and be able to use the newest releases and solve the issues the business requires.
There is also some performance reasons to move to a new SAP PO system because it optimized for faster processing of messages and easier maintenance. PO will also allow your users to interact with processes across the platform.
There are two approaches to it.
1) Upgrade the dual stack system to 7.5.
2) Fresh installation of 7.5 single stack
1) Upgrade to 7.5
With 7.5 the ABAP stack is separated out to a new system id. This feature enables you to delete the ABAP stack and giving you a regular 7.5 system.
There is also the option to upgrade and keep the system as a dual stack system. I don’t think it is a good idea because you are stuck with the same infrastructure and have to get away from the dual stack at some point.
The benefits are:
- That you don’t have to configure a lot of things again.
The challenges are:
- It will be a big bang implementation, and everything is moved at once. You better hope it will work after you have tested
- There is a requirement that you only have configured everything with ICO so it is a java only installation.
- You don’t have any ccBPM or that you can easily convert the processes in the upgrade.
- It is not a supported upgrade from SAP, but some partners can do with success.
- Long downtime while the update takes place
- You have to be migrating from a 7.31 or 7.4 system for this to be an option.
- It is difficult to perform any support while the operation takes place.
2) Fresh installation of PO
It gives you a fresh start on your development so you can configure the interfaces with the newest approach.
There is migration tool on SAP PO, which will allow you to migrate dual stack flow to ICOs. The tool has some limitations and will not be able to migrate everything.
The benefits are:
- You can migrate one interface at the time or in batches. So you will not have any downtime and can verify that the new system works.
- You can check the new adapters work if you are moving from a Seeburger AS2 to SAPs AS2 adapter.
- You can use the BPMN modeling tool from the beginning of the project.
- New platform running on newer hardware and operating system.
The downsides are:
- It takes a lot of time to move everything gradually.
- There needs to be coordination with partners to make sure that the messages work correctly.
- You will have two landscapes for a period that you will have to maintain.
Steps in the migration
A migration should consist of the following moving of objects.
1) Perform a proof of concept test to determine if the new system is working as expected. My experience has shown that there are non-critical messages with low volume that can be switched over to see if those work correctly, without risking the test on critical messages. If something is wrong with the process it is possible to do later.
2) Migrate the high-volume elements and continue to monitor how the migration is working. You want to be sure that your new system can handle the workload; although hopefully, it should be easier to get the same number of messages processed.
3) Move on to the critical interfaces. Now you have a proven system and you can move critical interfaces and make them run better on the new system.
4) Migrate the remaining interfaces. This is the part that can take a long time, especially if you have interfaces that run once a month or less.
5) If the business has requested any change to their existing interface, now is a good time to migrate those interfaces as well, since it will need to be done at some point anyhow. This also makes for a cleaner migration because you will have only one place where development needs to be done. If it involves three parties that will need to make changes, then it is best to migrate it all at the same time.
For both points, there are some challenges with the testing. You don’t want to test too much with the business. Business people often don’t care about such migration because it will not give them new ways to reach out to their customers.
There have been reported some changes in how adapters or message mappings work. They are not a big difference but if your application is using some of the features affect it can have a serious impact on your business.
You will need to ensure that messages processed will not be any different once they are processed on the new system. It can take some time but if you can perform it automatically, then you are far ahead.
There is the Integration Regression Tool from Figaf that allows you to easily test SAP PI/PO integrations. It does take some effort in getting up an run, but it will enable you to test better and with a lot more documents. It will also allow you to install patches more often and ensure your system is on the latest release.
Seeburger to B2B add-on
I wanted to have a full section on seeburger. Because it is one of the technologies that are going away. If you are using it it does have an enormous impact on your business.
If you are using Seeburger EDI converter or tools there may be quite a bit of extra work you will need to migrate.
Last time I checked Seeburger does not support on 7.5, so you will have to migrate all your Seeburger tools to SAP B2B add-on in the process. Even if Seeburger supported 7.5 it would still make sense to migrate because B2B Add-on has more features and can simplify your landscape.
The adapters are configured differently, so you will have to learn how to use the B2B Add-on adapters instead of the Seeburger version. There are some differences, so it is not possible to do an automated conversion of them. For instance is AS2 Partner number on the B2B Add-on adapter where seeburger is using the attribute from the parties selected.
For EDI handling there is also some differences.
For the EDIFACT, X12 messages the XSD structures is a little different, because some elements have been renamed and changed position. Users will, therefore, have to remap the two structures. This change can be done in different ways:
- Create a XSL(T)/Message mapping that can convert between the seeburger and b2b addon message. That way you can continue using your existing mappings. It will cost some runtime performance to do the conversion between the formats.
- Remap the message mapping to follow the new format. Repository helps with this. It will experience say it takes around 1 hour pr message.
- Remap using a tool like SMT from figaf. This does the smae as you would do in the repository but just automated. For more information see https://figaf.com/tools/seeburger-migration-tool/
The inbound processing of the EDI document is also different. You can use one connection for all inbound document because you can use the Trading Partner Management (TPM) to customize each partner.
The TPM many also enable you to restart all mapping all your messages so they follow the newest conversion. It is a big task but may simplify maintenance of your documents.