Seamless Instead of Clueless—SAP Interface Migration  

The Finnish chemicals group Kemira, with 5,000 employees, annual sales of 3.6 billion euros, 63 production sites and sales in over 100 countries, has made the switch to a new digital platform for the future in the cloud. The company has not only comprehensively digitalized the existing SAP ERP world and moved it to the S/4 Private Cloud, but has also converted the global integration landscape from SAP Process Orchestration to SAP Integration Suite.

The transformation project was named Leap for good reason, as it implemented five closely interlinked initiatives at the same time: the SAP S/4 transformation, the redesign of finance, the introduction of SAP Datasphere as an enterprise data warehouse, a digital data excellence initiative and the complete migration of 363 interfaces to the SAP Integration Suite. "At the time of the go-live, we knew that this was one of the largest and most complex interface migrations to SAP Integration Suite to date," says Holger Himmelmann, Consulting Director Enterprise Integration at cbs, assessing the scope. The big-bang go-live of the migrated interfaces took place at the same time as the S/4 go-live.

From assessment to implementation

The interface migration at Kemira is a blueprint for the cbs interface migration program "Integration Suite Uplift", which defines a standard approach for the migration of interfaces from SAP Process Integration / Orchestration to the SAP Integration Suite. The program ensures a successful migration by covering a comprehensive interface assessment, a roadmap definition and finally the actual migration up to the go-live of the interfaces. A few months before the migration, cbs consultants began analyzing the existing interface landscape and developing a migration roadmap. First, a basic integration strategy was defined using the SAP Integration Solution Advisory Methodology (ISA-M). The results of this first phase were tested using different scenarios to check their applicability and identify possible exceptions.

From As-Is to Replacement

Each interface was assigned a suitable migration approach, ranging from an "as-is" migration without technical adjustments to a "technology fit" or a "redesign" or "replacement", for example with SAP Pre-Packaged Con-tent. In addition, an estimate of the migration effort was made for each interface using T-shirt sizes. With the help of these results and the concrete project plan for the migration, the interface migration could be integrated into the Leap program. "We started with a high-level vision on a single PowerPoint slide, which basically showed a system landscape including all components relevant for the integration. During the assessment, we fleshed out this vision together with cbs until we had a clear integration design for each scenario. It was great to see how our initial idea became reality during the actual migration and how the cbs team gradually transformed the interfaces into the intended target architecture," says Miikka Vainionpää, Senior Manager, IT Enterprise Architecture and Integrations at Kemira.

During the assessment, the project team identified potential candidates for interface enhancements and redesigns that could be carried out with reasonable effort during the migration. 

Accelerate implementation

The aim was not to carry out a 1:1 migration, but also to create added value for the company, particularly with regard to the implementation speed of future interfaces. By carrying out the migration as part of the S/4 initiative, there was the possibility of a joint end-to-end test including all interfaces, which put less strain on the business units as all relevant people were available and assigned to the project anyway. The interface migration was carried out according to the motto "Reuse where possible. Redesign where it creates real added value". For interfaces in the "As-Is" category, mappings from the SAP Process Orchestra were imported into the SAP Integration Suite and reused.

The activities for interfaces in the "Technical Fit" or "Redesign" categories were much more complex: all existing Java mappings were converted into Groovy scripts. Lookups in the ERP back-end system within the middleware mapping, which previously took place via classic RFC calls, were replaced by calls to standard OData services or custom CDS views in S/4 Hana. This ensured future-proof and controlled access to data in the S/4 Hana backend, which poses no risk to the upgradeability of the system. XSLT mapping scripts in many existing interfaces were reused and adapted to the SAP Integration Suite.

In addition to the migration of the core interfaces, SAP API Management was introduced as a central API management layer to create a central access point for API-based integration scenarios. APIs were implemented accordingly for all incoming http-based interfaces in the Kemira network to ensure company-wide security standards. Classic file shares were replaced by an Azure Files Service, a file storage that provides web service-based access to the directory structure. All these aspects required additional adjustments to the interfaces, but were crucial in order to achieve a clean target architecture. During the project implementation, no out-of-the-box solution for Swift interfaces was available in the SAP Integration Suite. The cbs consultants implemented a customized solution with the option to replace these interfaces with content provided by SAP at a later stage.

One of the main challenges throughout the migration was to balance redesigns and improvements to interfaces with the reuse of existing artifacts in order to maximize the benefits and complete the migration of all interfaces in the specified time and quality. To achieve this, the architects from cbs and Kemira worked very closely together.

Testing the migrated interfaces on the SAP Integration Suite was a decisive factor in ensuring the correct implementation of all interfaces. For this reason, the project team decided to use the Figaf test tool to carry out interface regression tests. The cloud-based tool reads messages from the existing SAP Process Orchestration and processes them via the corresponding interface in SAP Cloud Integration. This test approach was used for large parts of the migrated interfaces and offered significant advantages in terms of test speed and traceability.

Going live

All initiatives of the Leap program were implemented in parallel and went live in a big-bang approach after a project duration of 15 months - record time for such a comprehensive transformation. Since then, all 363 interfaces have been running stably on the SAP Integration Suite and SAP Process Orchestration has been replaced. The redesigns carried out have led to more stable and smooth operation, while the clean overall interface architecture has increased the pace of development for new requirements. "Kemira has made the leap into the cloud company and digitized its entire process world. The Group is now in an ideal starting position. With the implemented platform, the company can tie in with all subsequent SAP developments and is always state of the art in terms of technology. This is a real innovative advantage over other companies that may not reach this level of development for another five years," explains cbs CEO Rainer Wittwen.   

The cooperation between Kemira and cbs in the field of integration does not end with the go-live. The trusting partnership will continue with cbs setting up a DevOps team at Kemira, which will take over both new developments and productive support for all interfaces on the SAP Integration Suite. In addition, cbs is currently developing a comprehensive concept for the integration of B2B partners with Kemira.

kemira.com

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