Systems & Software Engineering

Understand complex systems, connect engineering disciplines and validate behaviour earlier, with model-based and model-driven engineering.

From complexity to clarity

See the whole system. Test your thinking earlier.

Mechanical, electrical and software decisions influence one another. When requirements, architecture and behaviour are disconnected, teams struggle to see the consequences of change. Models create a shared engineering context, making complex interactions easier to discuss, assess and refine.

What changes for your team

A shared view across disciplines

Connect requirements, architecture, interfaces and behaviour so systems and software teams can reason about the same product, including its interaction with people.

From diagrams to executable behaviour

Model-based systems engineering (MBSE) makes the system explicit. Model-driven systems engineering (MDSE) takes suitable models further: execute and simulate behaviour to explore decisions before building physical prototypes.

Earlier feedback, clearer evidence

Use model-based tests to assess expected behaviour and explore complex scenarios. Validation evidence relates to the model, assumptions and test scope; it does not establish that a real system is free of unexpected behaviour.

System development maturity levels

Where are you today, and what is your next useful step?

From an idea that is difficult to communicate to a model whose behaviour can be examined: the System Development Maturity Levels describe seven ways to make engineering knowledge more explicit, executable and testable.

Use it as a discussion framework, not a race to the final stage. Choose a useful next step for your product, risks and team. Tools support the practice; owning a tool does not establish a maturity level.

  1. 01

    Idea

    An initial idea is not yet formalised and can be difficult to communicate. Capture it so others can explore it with you.

    Mind mapping and shared exploration

  2. 02

    Linear text

    Describe the idea in a document others can read and review. The intent is explicit, but relationships still need interpretation.

    Document-based description

  3. 03

    Structured text

    Organise the description around requirements, attributes and relationships, making individual needs easier to manage and trace.

    Requirements management · IBM DOORS

  4. 04

    Descriptive model

    Represent architecture, interfaces and behaviour with diagrams and text. A shared model makes the system structure easier to discuss.

    System modelling · IBM Engineering Rhapsody

  5. 05

    Executable model

    Run and simulate the model so the team can observe how the system behaves and explore interactions before implementation.

    Simulation · IBM Engineering Rhapsody

  6. 06

    Validated model

    Define tests for the intended behaviour and check the model against them. Make the test scope and validation evidence explicit.

    Model-based testing and test execution

  7. 07

    Proven model

    Investigate unintended behaviour with systematic verification and generated tests, within explicit assumptions and verification scope.

    Test generation and verification

The taxonomy is discipline-independent: mechanical engineering, software, analogue and digital electronics, and optics can use the same progression to discuss their engineering practice.

“Proven model” is the source taxonomy’s stage name, not a guarantee of defect-free software or safety certification. Conclusions depend on the model, verification method and coverage.

Towards the digital twin

Make virtual exploration useful before going further

Executable, validated models can support virtual experimentation and digital-twin development. The appropriate next step depends on what your model represents, which questions you need to answer and how it connects to your engineering environment.

Methods, tools and team capability

Explore UML and SysML, systems and software engineering methods, Rhapsody training, guidance and workshops, alongside the tools that connect requirements, models and tests.

Find your next engineering step

Bring your product challenges, existing models and tool context. Start with a 15-minute call.

Book a 15-min call