Sompo Japan Completes Successful Rehost Using TmaxSoft's OpenFrame Technology

Introduction
Sompo Japan has successfully transitioned from its legacy mainframe systems to a modern environment by implementing TmaxSoft's OpenFrame technology. This move is part of a broader strategy to optimize IT costs and ensure sustainable operations. The project kicked off in September 2021 and culminated in June 2025 with the launch of the rehosted systems, marking a significant milestone for the company.

The Path to Modernization

In this ambitious project, Sompo Japan opted for TmaxSoft's “OpenFrame7,” a cutting-edge rehosting solution capable of managing the intricacies of their existing systems. These systems, which had relied heavily on COBOL, JCL, and assembler languages, are mission-critical and essential for their operations. OpenFrame facilitated a seamless transition to Microsoft Azure, allowing Sompo Japan to harness its existing assets while upgrading to a more open and flexible IT environment.

Choosing the Optimal Solution

The insurance sector mandates a stable operational environment to consistently serve policyholders. However, maintaining a mainframe solution can be economically taxing, particularly given rising costs associated with hardware and software upgrades. Thus, after in-depth discussions about the characteristics and mission of its systems, Sompo Japan decided against rebuilding or rewriting processes. Instead, they embraced the rehosting approach, which promised a quicker transition with lower risks, while maximizing the usage of existing technological assets.

High Compatibility: The Deciding Factor

One of the pivotal motivations behind choosing OpenFrame7 was its impressive compatibility with existing programs, particularly those still utilizing assembler code. By preserving their legacy systems as much as possible, Sompo Japan aimed to maintain operational stability post-transition. The high compatibility with COBOL, JCL, and assembler languages offered by OpenFrame was key to ensuring minimal modifications during the transfer. This feature greatly impressed stakeholders and was crucial in moving forward with the project.

Comments from Sompo Japan

Sompo Japan remarked, “In this project, our foremost goal was to leverage our existing assets while ensuring the stability of our services. By employing OpenFrame, we have transitioned safely and reliably to an open operational environment. Moreover, we’ve significantly reduced our mainframe maintenance costs, which will now be redirected to enhance our digital services and drive our DX initiatives.”

Comments from TmaxSoft

The President of TmaxSoft expressed gratitude for the collaboration: “We are honored that Sompo Japan chose our OpenFrame for their modernization project. This initiative involved significant challenges, particularly in preserving the integrity of extensive legacy assets while migrating to an open environment. Close cooperation with Sompo Japan and all stakeholders involved ensured a smooth transition to production.”

What is OpenFrame?

OpenFrame is designed to transition existing COBOL, PL/I, assembler, and JCL applications from mainframe systems to more modern open and cloud environments. It enables organizations to adopt new technologies with lower risks and costs compared to traditional approaches like rebuilding or rewiring. Notably, OpenFrame has garnered traction among financial institutions and public sector bodies, showcasing its versatility.

About Sompo Japan

Founded in 1888, Sompo Japan originated as Japan's first fire insurance company and currently stands as the backbone of the SOMPO Group's domestic insurance services. Beyond offering insurance products, the company actively addresses societal issues through various initiatives, such as disaster prevention services and community engagement projects aimed at enhancing overall safety and health.

About TmaxSoft

Established in 2000, TmaxSoft Japan is a subsidiary of TmaxSoft from South Korea. It specializes in providing various solutions, including OpenFrame7 for legacy modernization, Tmax for TP monitoring, and JEUS for web application servers, contributing significantly to the technological landscape of their clientele.