MOSA Is Moving from Principle to Practice

While a defense platform designed today may serve for decades. The sensors, software, and communications systems inside it may need to change in just a few years.

A modular open systems approach (MOSA) can give defense organizations more flexibility to integrate new technologies, work with different suppliers, and upgrade systems throughout their operational lives.

But a modular architecture alone does not guarantee that flexibility. Defense programs also need usable interfaces, appropriate data rights, and access to the information needed to manage change.

Digital engineering helps connect the requirements, architecture, software, configurations, and verification evidence that programs need to put MOSA into practice.

Moving MOSA into practice

MOSA aims to make aerospace and defense systems easier to upgrade by establishing modular components and well-defined interfaces.

Consider a program integrating a new sensor into an existing platform. The sensor may meet its individual requirements, but the program still needs to understand its effects on software, physical interfaces, cybersecurity, verification, and the approved system configuration.

If that information is difficult to access, teams may spend valuable time identifying dependencies before they can assess the change. Connected engineering information helps them understand the impact, coordinate the organizations involved, and maintain control as the system evolves.

Four foundations for putting MOSA into practice

MOSA cannot be achieved through any single engineering tool. It requires coordinated acquisition and engineering practices, supported by information that’s connected across the lifecycle.

1. Define modular architectures and interfaces

Effective modularity starts with decisions about where to establish boundaries and how components will interact.

Model-based systems engineering (MBSE) helps teams define system architecture, interfaces, and dependencies while connecting them to mission and system requirements. Programs can then apply modularity where it creates the most value, based on mission needs, anticipated technology changes, and opportunities for supplier competition.

Interfaces should be clearly defined using appropriate open or widely supported standards, with information available in forms authorized suppliers can use. A practical test is whether a qualified supplier can use the defined interface to integrate or replace a component without unnecessary changes to the larger system.

2. Address technical data and data rights early

Programs need access to the information required to integrate, maintain, and upgrade system elements. That includes models, interface definitions, product information, and other technical data.

Program managers and acquisition teams should address data access, intellectual property, and sustainment needs early in the acquisition strategy. Digital engineering can support that strategy by helping organizations govern technical information and control access according to security, intellectual property, and program requirements.

3. Connect engineering information across tools and organizations

Defense programs span government organizations, primes, suppliers, engineering disciplines, and generations of technology. Their engineering environments need to connect information across those boundaries.

Open standards, APIs, model exchange, and federation can help teams share and reuse engineering information across tools and organizations. The level of exchange depends on the standards, integrations, and access controls used by each program.

This becomes especially important when a new supplier joins a program or an existing system needs an upgrade. If teams must recreate models, translate data manually, or rebuild engineering context, integration becomes more difficult and the flexibility promised by modularity is harder to realize.

4. Manage and measure change

Introducing a new capability requires teams to understand which requirements and interfaces are affected, which configurations must change, and what needs to be verified again.

Connecting this information helps teams assess the impact of a proposed change and manage technology insertion with greater control.

Programs can assess whether modularity is delivering its intended benefits by asking:

• Can a qualified supplier access and use the information needed to integrate with an interface?
• What changes to the larger system are required when a module is replaced?
• Can teams identify the requirements, configurations, and verification activities affected by a change?
• How much time and effort does it take to integrate and verify a new capability?

Together, these questions can help programs identify where interfaces, data access, or engineering processes limit their flexibility.

Digital engineering in practice: American Rheinmetall

American Rheinmetall illustrates how digital engineering and modular design can support the development of adaptable defense systems. Working with technology and manufacturing partners, the company is designing its next-generation combat vehicle with the flexibility to integrate future technologies and capabilities.

As part of its broader digital engineering approach, American Rheinmetall uses PTC Creo for top-down design and skeleton modeling to coordinate complex vehicle assemblies, manage component dependencies, and consider downstream manufacturing requirements. These engineering practices support the coordination and change management needed to develop modular systems that can evolve over time.

Connecting MOSA across the engineering lifecycle

Putting MOSA into practice depends on architecture decisions, interface standards, data rights, acquisition strategy, and governance. Digital engineering supports those decisions by helping teams manage the information behind them.

PTC helps defense organizations connect the engineering information needed to define modular systems, assess changes, manage configurations, and support verification across the lifecycle:

• PTC Modeler supports system architecture definition
• Codebeamer manages requirements, software development, and verification
• Windchill manages product information and configurations
• Pure Variants supports variability and reuse
• Creo supports detailed product design

Returning to the sensor example, connected engineering information can help teams identify how a proposed upgrade affects requirements, architecture, software, verification activities, and product configurations.

PTC also supports integration and information exchange across heterogeneous engineering environments, helping organizations connect work across disciplines and suppliers while maintaining governance and configuration control.

Engineer for continuous modernization

MOSA gives defense programs a foundation for evolving capabilities over the life of a platform. Digital engineering helps teams understand the impact of change, control configurations, coordinate suppliers, and verify upgrades.

With those foundations in place, organizations are better positioned to introduce new technology, expand supplier options, and modernize systems as mission needs change.