To address the complexity of core system infrastructure overhaul, phased sizing was combined with a flexible virtualization platform, achieving information system infrastructure migration while minimizing downtime.
Shikoku Electric Power Co., Inc. has been developing business systems using SAP ECC 6.0 in three operational areas: accounting and materials management, nuclear power plant maintenance and sales. In particular, the accounting and materials management system (Enterprise Resource Planning, hereinafter the “ERP system”) has been in operation for many years and used by 13 group companies.
Against this backdrop, the end of maintenance support for ECC 6.0 has become a major challenge. Since this is a critical system supporting core business operations, migration to S/4HANA is unavoidable to ensure long-term stable operations. It requires careful consideration regarding the massive data migration effort, business continuity measures during system downtime associated with the migration, and the establishment of rollback procedures in case of operational issues. In particular, the initial S/4HANA migration project for the ERP system faced difficulties in accurately sizing servers during the early stages, and it was unclear whether migrating the massive volume of data from the current system to S/4HANA’s in-memory database (HANA DB) would result in stable operations. Consequently, the project carried the risk that insufficient resources in the IT infrastructure could impact the entire migration plan.
To address these challenges, Shikoku Electric Power adopted an approach of gradually adjusting its resources. First, the company added memory to its existing IBM® Power9 (E950) servers to build development servers and accurately determine the actual capacity required by S/4HANA. Based on this, the company decided to properly size the systems, starting with the quality assurance servers and moving on to the production servers, while verifying the load and requirements, and adding necessary memory and other resources required at each stage.
Meanwhile, as it proceeded with the ERP system migration project to S/4HANA, the company needed to address the upcoming end of maintenance services for CIS Power 8 (S824).
To this end, plans were reviewed to ensure quality for the Power9 (E950) and add memory for production servers, and in line with the replacement of CIS Power 8 (S824), the latest IBM Power10 (E1050) was introduced as a foundation capable of supporting the ERP system. In addition to high processing performance and large memory, CPU resource sharing using the IBM PowerVM virtualization platform and Shared Processor Pool enables stable resource allocation even in environments where multiple systems run concurrently, such as S/4HANA, ECC6.0 and other applications, enabling adaptability for sudden workload increases.
Further, with an eye toward post-migration operations, Shikoku Electric Power adopted a configuration that enables rapid activation of physical cores, allowing the company to flexibly address future S/4HANA performance improvements and the preparation of development environments. As a result, the company has established a flexible IT infrastructure capable of responding swiftly to future changes in business operations.
When migrating to CIS Power10 (E1050), a migration method utilizing high-speed data copying between IBM Storage systems (from V7000 to FS7200) was adopted to minimize downtime. This greatly compressed the workflow involved in server migration, minimizing operational impact and allowing the migration to the new server to be completed in a single day.
Shikoku Electric Power steadily advanced a long-term project spanning three years and completed the full-scale transition to S/4HANA during Golden Week 2025 as planned. Since then, it has continued to operate without any issues in processing performance or stability.
In addition, by utilizing the remote copy feature of IBM Storage, the server migration—which previously took about five days—was completed in just one day. This significant reduction in downtime made it possible to proceed with the migration while avoiding periods of high impact, which greatly contributed to ensuring business continuity.
Also, by optimizing resources using IBM Power virtualization technology, the company reduced server software costs by approximately 54 million yen. The flexible CPU allocation provided by the Shared Processor Pool ensured stability even when multiple servers were running concurrently during the development and testing phases, significantly mitigating risks during the migration period.
The insights gained from this initiative are expected to be useful for the EAM migration scheduled for fiscal year 2026. Approaches such as phased sizing, migration methods that leverage storage features to minimize downtime, and resource design that ensures stable operation even in a coexisting environment will also be effective for similar large-scale core system overhauls.
In addition to improved maintainability and operability by enabling centralized operation of ERP systems—including production, verification and development environments—IBM Power's IaaS service Power Virtual Server supports SAP's Cloud ERP (RISE with SAP). This makes it easier to accommodate future migrations to cloud environments. These results are expected to be useful in solving challenges such as reducing software license costs, number of servers and rack space.
Teruyuki Hamagami, Infrastructure Development and Optimization Group Leader in the Information Systems Department of Shikoku Electric Power (as of March 2026), comments, "We have been using IBM Power for some time. It's an outstanding, robust platform, and we haven't experienced any infrastructure failures. We place great trust in IBM Power as the foundation for critical systems requiring high availability. In addition, per-core performance has improved dramatically, and we look forward to even greater integration moving forward."
As an enterprise responsible for power supply in the Shikoku region, Shikoku Electric Powerprovides stable power services while embracing business transformation utilizing digital technology. Further, with the aim of creating new value that will be a source of future revenue, the company is expanding its business domain in diverse fields such as comprehensive energy, information and communication, and business and lifestyle support. While utilizing technology and expertise cultivated over many years, the Shikoku Electric Power Group is working to provide services that reflect the industry characteristics of the Shikoku region and meet customer needs.
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