Model Based Systems Engineering (MBSE): A Better Way to Engineer Systems
In traditional systems engineering, the source of truth lives in documents and spreadsheets. As a result, changes ripple manually, traceability is fragile, and diagrams often drift from reality. By contrast, Model Based Systems Engineering (MBSE) makes the model the system’s living source of truth. In practice, the shared model (often in System Modeling Language SysML) expresses structure, behavior, requirements, and interfaces, which enables consistent views, rigorous analysis, automation, and reliable traceability across the lifecycle.
Systems Engineering vs MBSE
Growing product complexities and industry demands have created a whole host of engineering challenges. Moreover, increased functionalities and intricacies of engineering systems has made software the dominant share of any given product’s cost and capability. Consequently, the system must communicate with the supporting sub-systems. There is also a need for standards within the industry, and regulating those standards for compliance and certification.
Therefore, systems engineers typically use a myriad of documentation tools as a way of visualizing all phases of the development process. This includes conceptualizing, designing, writing requirements, and traceability.
SysML: Breaking Down Silos in a Fragmented Engineering Landscape
This fragmentation leads to several specific problems:
- Engineers must become proficient in multiple complex platforms, creating inefficiencies
- Maintaining consistency across system models becomes difficult
- Communication and shared information between different disciplines is virtually nonexistent without a common language
- Teams often resort to using general-purpose tools like MATLAB, Excel, and specialized requirements management tools that don’t always work together effectively
Implementing a common language like SysML establishes better understanding and facilitates collaboration between disciplines. Engineers can capture concepts and designs in one system, which ensures shared values and gives everyone the same understanding of the development stage.
A standardized approach also enables better impact analysis against software and systems and helps create one cohesive workspace for systems engineers.
A sophisticated tool that provides both the underlying database and the diagrams that provide views onto the data is necessary. With the growing intricacies of modern systems and lack of standardization across platforms, it is no wonder that engineers are developing a preference for creating models of systems to visualize systems. As a result, Model Based Systems and Software Engineering (MBSE) techniques are becoming the industry norm for expressing systems and software architectures.
SysML – The Common Language
SysML can be used to capture concepts and design into one system. When the information is in one place, the system will have shared values, and engineers will have the same idea of the development stage. Without this form of modeling, communication and shared information between the different disciplines is virtually nonexistent. This method enables engineers to perform better impact analysis against the software and system. SysML is more than a diagramming notation. It also defines the properties of the elements on the diagrams, and the relationships between them.
MBSE: The Model-Centric Shift
Model-based systems engineering (MBSE) has been defined as “the formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases.” Other engineering disciplines, including mechanical, electrical and software, have adopted this model-centric approach as part of a long-term trend. MBSE represents a fundamental shift from traditional document-centric practices that systems engineers have used in the past. MBSE is expected to replace document-centric approaches and redefine systems engineering processes.
Applying MBSE typically provides significant benefits over document centric approaches. It enhances productivity and quality while reducing risk. MBSE also improves communications among the system development teams. Standardized languages define systems of systems across various industries. As systems and their models grow increasingly complex, engineers need new ways to organize the models and verify the decisions they make while creating them. This will enable engineers a means to reuse assets while making value-based decisions on system configuration.
Design & Build the Right Systems, Right
The solution is to design before you build with a standards-based graphical modeling tools such as PTC Integrity Modeler, Catia Magic, IBM Rhapsody, or Enterprise Architect. Building a model with any of these platforms establishes a common language (SysML). This improves understanding and facilitates collaboration between the disciplines. With MBSE, problem abstraction occurs, and the systems engineer can see the proverbial forest for the trees.
Improved Systems + Reduced Time + On Budget = Maximized ROI
Process Automation or efficiency within the entire engineering process is just one of the naturally occurring benefits of using this type of modeling. With tangible designs to review, finding problems are easier and occur earlier. Traceability of requirements from models to the system is a snap, as is rapid prototyping, simulation and trade studies.
The learning curve is worth the long-term cost reduction. MBSE can cut development costs by 55%. It delivers 62% more products on time versus standard systems engineering (EMF 2013 Independent Survey Results from 667 systems engineering respondents). In today’s budget constrained world these are numbers that demonstrate a return on investment that is worth investigating.
James Hummell is an expert trainer in SysML, UML, and UPDM/UAF, currently serving as founder and principal of MBSE Solutions, a tool gnostic (as opposed to tool agnostic) training and consulting company. With expertise in software and systems engineering, he specializes in modeling and simulation analysis using UML and SysML. For over 20 years, he has been developing software and systems using model-based design engineering. As a member of the RTCA SC-205 subgroup, he contributes to developing the DO-178C Model-Based Development and Verification Supplement. His work with OMG and INCOSE spans various specifications and working groups. James holds a degree in Computer Engineering from the University of Arizona.
