If you lead an IBM i environment, you’ve probably heard every version of the same advice: “Rewrite it.” “Replace it.” “Move it all at once.”
On paper, that sounds clean. In reality, it’s how transformation projects slip, stall, or create avoidable risk. IBM i applications aren’t isolated programs — they’re ecosystems of interdependent logic refined over decades. That logic isn’t something to escape. It’s something to futurize: extend safely, incrementally, and with measurable value along the way.
The real question isn’t whether futurization is needed. It’s how to do it without betting the business on a big-bang cutover.
That’s exactly what coexistence enables — and why our approach to coexistence is foundational to safe IBM i futurization.
Understanding the Transformation Dilemma IBM i Teams Live With
IBM i leaders are navigating a perfect storm: retiring RPG/COBOL talent, growing technical debt, and escalating expectations for modern capabilities like APIs, AI integration, and improved user experiences. Futurization is urgent, but it also has to be safe.
And safety is hard in IBM i environments because every program is connected. A typical RPG or COBOL application touches dozens of database tables and calls many other programs across the ecosystem. Disrupt one component, and you risk cascading failures across the system.
That’s why the approach matters more than the ambition.
Big bang vs. Coexistence: Two Paths, Very Different Outcomes
A big-bang strategy replaces major components of the system all at once. On a slide, it looks efficient: one cutover, one new stack, one finish line. In reality, IBM i ecosystems rarely behave that neatly. Because applications are tightly interwoven, big-bang futurization concentrates risk into a single moment. That means long, multi-year timelines before value is visible, heavy validation pressure as the finish line approaches, and a cutover week where any missed edge case can ripple into business-critical failure. If everything lands perfectly, you win late. If it doesn’t, the business absorbs the blast radius.
A coexistence strategy takes the opposite posture.
Instead of forcing the entire ecosystem to change at once, legacy and futurized components run side-by-side while you transform incrementally. That side-by-side model matters because it lets you futurize one slice at a time — a program, a screen, a service — without breaking downstream dependencies. You can prove functional equivalence in smaller, safer steps, roll out improvements earlier, and keep a fallback path if anything behaves unexpectedly.
Most organizations can’t afford the risk or delay of big-bang transformation. They need faster results and operational continuity. Coexistence is how you get both.
The Hidden Advantage: Value Shows Up Early
The biggest benefit of coexistence isn’t technical. It’s operational. Coexistence lets you deliver measurable wins before the full futurization journey is complete.
For example:
- Deploy a new UI while the legacy backend still runs
- Futurize a high-value module while dependent legacy programs continue calling it safely
- Improve workflows step-by-step without waiting for a full system conversion
End users feel progress early. Your team reduces risk continuously. Futurization becomes a steady, confident path instead of a once-a-decade gamble.
Why Coexistence is the Safest Road to IBM i Futurization
When you step back, coexistence wins because it aligns with the realities of IBM i systems and the expectations of modern IT leadership:
- Coexistence lowers risk because nothing hinges on a single cutover moment.
- It accelerates value because improvements ship while futurization continues.
- It lowers costs because automated connections replace manual patching.
- Quality improves because dependency rewiring is consistent and repeatable, not hand-built.
- And flexibility increases because futurization can follow business priority instead of being trapped by technical interdependence.
Coexistence is what makes futurization incremental, measurable, and safe — exactly what IBM i leaders need.
Your Next Step: Start small, futurize confidently
The IBM i organizations that lead the next decade won’t be the ones abandoning proven systems for risky rewrites. They’ll be the ones futurizing what already works, one safe slice at a time.
Coexistence makes that possible.
If you want to explore what coexistence-driven futurization looks like in your environment, reach out to our team at Futurization@ProfoundLogic.com. We’ll help identify a high-impact starting point, prove value quickly, and build a phased path forward, without downtime and without big-bang risk.