Endevor to Git/GitLab
The most common path, especially in financial services.

ChangeMan to GitLab
Often motivated by broader enterprise DevOps modernization.

Hybrid transition
Git handles source; legacy SCM controls promotions until automation matures.

Full replacement
Git or GitLab manages SCM, and CI/CD pipelines fully replace legacy promotion workflows.

No two migrations are identical. The technical landscape, regulatory needs, and organizational culture all shape the modernization path.

6. Why Mainframe SCM Modernization Is Not a DIY Project

It is tempting for organizations to approach mainframe SCM modernization as an internal engineering task: convert the repositories, configure the pipelines, train the developers, and migrate the workflows. In practice, however, these initiatives consistently prove to be complex, multi-layered transformations that touch nearly every part of the software delivery lifecycle.

Firms that specialize in mainframe modernization, DevOps enablement, and toolchain integration consistently highlight the same themes: organizations routinely underestimate the technical depth, cross-system dependencies, and sequencing discipline required to successfully replace Endevor, SCLM, or ChangeMan with Git or GitLab.

Several factors contribute to why this is not an ideal do-it-yourself effort.

The Technical Landscape Is Highly Interdependent

Legacy SCMs are not isolated tools; they sit at the center of a mainframe ecosystem that includes:

• promotion models
• compile and link-edit processes
• DB2, IMS, and CICS integration
• batch scheduling
• deployment automation
• regulatory audit dependencies
• exit routines and extension logic

Each dependency must be understood, mapped, and re-implemented in the new toolchain. Missing just one integration point can break downstream workflows or destabilize production systems.

Migration Requires Precise Sequencing and Change Control

Modernization involves:

• restructuring source assets
• defining new repository layouts
• determining appropriate branching strategies
• establishing automated build pipelines
• validating promotion workflows under load
• aligning test and quality gates with compliance needs

A mis-sequenced step can generate regressions, create promotion gaps, or leave the organization without a reliable rollback path. Successful migrations follow a rigorously designed sequence that accounts for technical, operational, and regulatory requirements.

Internal Teams Often Lack Cross-Platform Experience

Mainframe specialists understand COBOL, JCL, DB2, and RACF.
Distributed DevOps teams understand Git, GitLab, CI/CD, containers, and automated testing.

SCM modernization requires both.

The most common failures occur when organizations rely solely on one side of the skill set. The result is either a technically correct migration that is operationally unusable, or a modern toolchain that does not faithfully replicate critical mainframe governance and promotion rules.

Tooling Choices Have Long-Term Architectural Impact

Decisions made early in the migration — such as repository design, branching models, and CI/CD architecture — shape the next decade of development. Poorly designed structures lead to merge bottlenecks, excessive branching complexity, audit gaps, or pipeline performance issues.

The responsibility for these decisions should not fall on teams with limited prior modernization experience.

Hidden Risks Can Lead to Significant Business Disruption

Similar to what modernization specialists emphasize, the risks in a DIY approach include:

• unrecognized dependencies between legacy environments
• misaligned promotion logic that allows changes into production unintentionally
• pipeline designs that do not enforce required quality or compliance controls
• lack of rollback mechanisms
• disruption of parallel releases or emergency fixes
• unexpected outages due to improperly sequenced configuration changes

These risks carry real cost and reputational impact, particularly in regulated or customer-facing industries.

The Value of Working with an Experienced Modernization Partner

Organizations that partner with a specialist benefit from:

• experience designing migrations across multiple SCM platforms
• predefined patterns, accelerators, and reference architectures
• proven sequencing and risk-mitigation strategies
• deep familiarity with both mainframe workload constraints and modern DevOps tooling
• faster time-to-value and reduced experimentation
• confidence that promotion logic and audit requirements are preserved
• smoother cultural transition for developers and operations teams

A partner can guide the organization through planning, architecture design, workflow transformation, migration execution, and team enablement — reducing risk while ensuring the modernization effort produces measurable ROI.

A well-executed migration is not only possible — it becomes a competitive advantage. But it requires expertise, cross-platform understanding, and structured guidance that most organizations do not have internally.

Conclusion

Mainframes remain strategically important. What is changing is how development teams collaborate, review, test, automate, and deliver high-value updates. Transitioning from legacy SCM tools to Git or GitLab is no longer simply a tooling upgrade; it is a modernization strategy that reduces cost, aligns the mainframe with enterprise DevOps workflows, and improves delivery performance.

The organizations taking this step today are future-proofing both their mainframe environments and their development teams.

If you’re exploring a move to a modern SCM environment, 321 Gang can help you evaluate options and build a practical roadmap. Contact us to start the conversation.