Bridging the Gap: Aligning Systems and Software Architectures for True Interoperability

Because disjointed architectures cost time, money, and mission adaptability. 

THE DISCONNECT WE CAN’T AFFORD 

Imagine building a skyscraper with two different blueprints—one for the steel structure and one for the plumbing—without ever reconciling them. Each looks complete on its own, but when it comes time to integrate, the pipes run through the beams. 

That’s the situation too many government and commercial programs face today. Systems engineers define mission intent, functions and interfaces. Software teams design execution logic, data flows and integration patterns. Both are essential, but too often they are developed in silos. The result? Mismatched interfaces, late-stage integration crises, costly rework and brittle systems that can’t adapt when missions or markets shift. 

BEST PRACTICES FOR CLOSING THE GAP 

1. Shared language and standards 

   • Use model-based systems engineering (MBSE) to define interfaces in ways software teams can directly consume [e.g., SysML-to-Unified Modeling Language (UML) mappings and auto-generated interface control documents (ICDs)]

   • Ground architectures in Modular Open Systems Approach (MOSA) standards like the, Future Airborne Capability Environment (FACE), C5ISR/EW Modular Open Suite of Standards (CMOSS), and Sensor Open Systems Architecture (SOSA) to ensure definitions are portable, interoperable and traceable 
     

2. Architect for flexibility 

   • Apply classic software best practices (loose coupling, high cohesion) to the system-of-systems level 

   • Utilizing encapsulated line replaceable units (LRUs) to decouple low-level hardware and software, allowing for design evolution without compromising architectural integrity  
     

3. Digital thread for traceability 

   • Ensure requirements → system model → software modules → test cases are digitally connected 

   • This reduces ambiguity and eliminates “lost in translation” moments between disciplines 
     

4. Continuous alignment mechanisms 

   • Hold recurring architecture syncs between systems and software teams 

   • Employ digital engineering pipelines, enhanced by AI where possible, to validate consistency between system and software models in real time 
     

5. Living architectures, not static documents 

   • Architectures should evolve as missions, technologies and threats change 

   • A living architecture is an asset; a static document is a liability 

REALITY CHECK: BALANCING PROCESS AND INNOVATION 

Textbook systems engineering says start “pure”. Meaning, treat software as a black box early and open it into white box detail later. In theory, this preserves separation of concerns. 

In practice, modern programs don’t work that way. Software enters the conversation from day one: 

• Feasibility checks: Can this function run on available processing power and meet safety or latency needs? 

• Candidate architectures: Partitioning decisions and middleware choices shape what’s viable 

• Risk identification: Autonomy, AI/ML and cybersecurity challenges can’t wait until late integration 

This isn’t process failure, it’s reality. The real challenge is balancing process discipline with innovation impulses. 

That’s where systems engineering and MBSE prove their value. Instead of discouraging early solution ideas, they structure and capture them: 

• Candidate solution architectures include software considerations without locking into premature commitments 

• Risks surface early, giving leaders time to mitigate 

• Innovation flourishes inside a disciplined framework that strengthens the design instead of derailing it 

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MBSE LETS US HAVE IT BOTH WAYS: FREEDOM TO INNOVATE, DISCIPLINE TO SUCCEED 

Case in Point 

• Defense: Programs have lost months reconciling misaligned ICDs between platform integrators and software vendors. With model-driven interfaces, those mismatches are caught in design, not after field tests 

• Commercial: Automotive EV platforms use modular architectures to support multiple vehicle models and deliver software updates over the air – proof that aligned systems and software architectures accelerate adaptability 

  
  

THE PAYOFF: TRUE INTEROPERABILITY 

When system and software architectures reinforce one another, programs deliver: 

• Reduced integration cost and schedule risk 

• Faster refresh cycles and technology insertion 

• Resilient systems that adapt to evolving missions and markets 

The truth is simple: architecture is not documentation. It’s the engine of adaptability. 

The real question for leaders is whether your system and software architectures are designed to evolve together—or whether you’re waiting to discover the conflicts when it’s too late.