MBSE 2.0 — Finding the Right Path

More and more, we are starting to think of model-based systems engineering—MBSE—as entering its next iteration. In what we are seeing as “version 2.0,” MBSE is not so much a new, augmented and revised edition of the model-based approach as it is a return to and a re-emphasis on its original principles and with that, its power and potential.

From its outset, MBSE has harbored a tremendous potential that springs from its power to provide an integrated model of highly complex systems. Out of the MBSE system model flows a rich variety of possible views of the system problem and design, each one a window into different aspects seen from different perspectives on the system. When the model is grounded in a robust systems metamodel, all of its elements are held in consistent relationships to each other, and the views become an avenue to understanding the system—from design trade-offs to the implications of physical design choices.

The consistency of structure offered by the systems metamodel framework makes it possible to reuse the lessons learned and designs created from project to project. Its rigor assures the designers of internal consistency and completeness. Paired with a powerful tool that instantiates the systems metamodel as its database schema, even the most complex design can be modeled implementing the full rigor and structure of MBSE.

But, as is often the case with new approaches, the wheels have begun to come off the MBSE bus. The common inclination to see the approach itself as a process rather than a principled methodology has been exacerbated in the systems engineering world with its process-based focus and history. Rather than understanding the principles behind the power of MBSE, many practitioners have moved immediately to implementing what they see as its practices.

As an example, the MBSE concept of a system design model as the “model” in “model-based” has regularly been lost in the temptation to use any design-related model to make their designs “model-based.” Others have sought to cobble together a system model using the loosest interpretation of what meets the definition of “model.” In this “modeling by aggregation” approach, views and documents and lists of requirements with no internal connections among them have been added together to become a substitute for the real, integrated model capable of supporting the true value of MBSE. In short, the systems view, a fundamental requirement for good systems engineering, has frequently been sacrificed or ignored.

In these awkwardly constructed aggregations it is easy for inconsistencies and incompleteness to hide. The more complex the reality being modeled, the easier it has been to miss those problems. That has robbed the MBSE model of the exact benefit—the ability to wrangle complexity—that was from its inception its most powerful promise.

The problems with process emphasis, neglect of principles, and the lack of integrated systems models have paved a path away from the promise and power of MBSE. MBSE 2.0 represents a call back to the power and promise of the original MBSE journey.

How is that call finding expression in MBSE 2.0? The new call is offering solutions to the problems and mistakes of the old path. First and foremost is the call to return to taking the systems view by basing our designs on an integrated system model built on the framework of a declared, proven systems metamodel. (See The Meaning is in the Metamodel, and Who Needs a Metamodel?) The systems metamodel is foundational to unlocking the power of model-based systems engineering models and is the first call of MBSE 2.0.

The model that we make in MBSE 2.0 must also be based on solid engineering. There are two legs to model-based systems engineering. We tend to focus on the necessity of having a model in order to be “model-based.” But we cannot miss the fact that sound systems engineering is also required. Good MBSE requires both good models and good engineering. MBSE 2.0 reminds us of that and calls us to focus on good systems engineering.

MBSE 2.0 also reminds us that we have the power through its models to connect all of the engineering that goes into the system life-cycle. While the analytical and life-cycle models are not the models that make MBSE model-based, they do provide important insights. The ability to connect to them and the disciplined engineering around them enriches the system model and adds to its power. MBSE 2.0 calls us to make those connections and benefit from the power of connected engineering.

Given this understanding, the steps to MBSE 2.0 should come as no surprise. First, we must understand and commit to the necessity of good systems engineering practices and taking the systems view. We must adopt a robust, declared and proven systems metamodel to provide the framework for our models. In order make this actionable, we must adopt a true systems engineering tool that incorporates the systems metamodel and offers an integrated systems view in a single model. Any effective systems engineering tool must offer the means to enable truly connected engineering. These steps will put us back on the path that is the object of the MBSE 2.0 call.

The power of integrated system models couched in a declared, proven systems metamodel has always been attainable through MBSE. So have the benefits of connected engineering and analytic models. MBSE 2.0 calls us to reclaim them by recovering the practice of the principles of MBSE. We ignore that call at the peril of our projects and stakeholders.

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