Systems engineering modeling languages must be capable of handling the complexity of the systems they describe, while also supporting the practical needs of the engineers and stakeholders who use them throughout the development lifecycle.
SysML has played a pivotal role in advancing systems engineering by providing a widely adopted, domain-specific modeling language. Its broad acceptance helped unify the community around a shared understanding of the value of formal modeling in designing increasingly complex systems. Now that SysML v1 has been widely applied in real-world projects, several shortcomings have become apparent, highlighting opportunities for refinement in areas such as semantic clarity, comprehensive coverage of systems engineering technical processes, and accessibility for both engineers and non-technical stakeholders.
Vitech’s Comprehensive Systems Design Language (CSDL) is designed to meet these evolving needs, offering enhanced clarity, semantic depth, and broader conceptual coverage.
Here’s why CSDL is worth a closer look.
1. Natural Language Modeling for Real-World Communication
CSDL is built on a natural-language foundation, using Entities, Relationships, and Attributes (ERA) to model systems in a way that mirrors how humans think and speak. This means models are not just technically accurate – they’re readable and relatable.
For example, if you want to relate a function called “Generate Mechanical Energy” to a Component called “Engine”, the graphical syntax can be read to make a simple sentence: “The “Generate Mechanical Energy” function is performed by the “Engine” component.”
Figure 1: Example of a simple, easy-to-interpret CSDL diagram
SysMLv1, by contrast, relies heavily on esoteric graphical notation and UML semantics originally developed for software engineers, which can be intimidating for non-engineers and difficult to interpret without specialized training. While SysML v2 has divorced itself from UML, the complexity of the graphical notation has continued to increase, which can be argued creates an even steeper barrier to effective communication with interested stakeholders.
Figure 2: Example of a SysML v1 Block Definition Diagram (BDD) used to convey functional decomposition. The diagram includes specialized relationship notation, stereotypes, multiplicity, part usage names, and conditional statements that may be foreign to most stakeholders.
With CSDL, stakeholders across disciplines, ranging from engineering, business, operations, can engage with the model directly via easy-to-understand concepts, fostering true cross-functional collaboration.
2. Unified, Holistic Modeling
CSDL is designed to support the entire system lifecycle covering requirements, functional architecture and behavior, structural architecture, and verification & validation. It even extends to program management and specialty engineering, offering a single source of truth for all aspects of the system.
In contrast, SysML v1 requires extensions or companion tools to cover the full scope of systems engineering technical processes. Even SysML v2, while improved, still depends on modular semantics and external integrations to achieve similar coverage.
3. Rapid Adoption and Ease of Use
One of CSDL’s greatest strengths is its low barrier to entry. Engineers can start modeling without needing to master a complex language specification. Tools like GENESYS and Sidekick provide intuitive interfaces, drag-and-drop modeling, and automatic diagram generation.
SysML has a steep learning curve. To model effectively, engineers must first grasp specialized UML concepts originally developed for software engineering, navigate complex diagram syntax, and adapt to tool-specific implementations. This makes it challenging for many systems engineers to get started quickly or work efficiently without extensive training.
CSDL empowers teams to focus on engineering, not on learning a language.
4. Stakeholder Engagement Through Sidekick
Vitech’s Sidekick platform brings CSDL-based models to the web, enabling interactive review, commenting, and collaboration. This democratizes MBSE, allowing customers, managers, detailed design teams, and domain experts to participate in model development without needing specialized tools or training.
With Sidekick, CSDL enables a living model: accessible, transparent, and collaborative.
5. Built-In Validation and Consistency
CSDL brings built-in semantic rules that guarantee model integrity from the start. When implemented in tools like GENESYS, relationships are automatically validated, and inconsistencies are flagged in real time. Every diagram is guaranteed to remain consistent with the underlying data model, eliminating the risk of modeling errors and keeping the system design coherent as it evolves.
In contrast, pure SysML models often suffer from fragmentation and inconsistency. As implemented in many popular modeling tools, diagrams typically require manual updates to stay aligned with the latest model data, leading to uncertainty about whether any given view reflects the true state of the system. Maintaining consistency in traditional SysML environments demands constant attention from highly skilled modelers.
With CSDL, these issues simply don’t arise. Its intelligent structure ensures models are integrated and consistent from the beginning, saving time and reducing schedule risk. Stakeholders can trust that what they see is accurate, whether it’s a native CSDL view or an automatically generated SysML diagram.
CSDL’s built-in intelligence keeps your model clean, connected, and correct – all by design.
6. It Doesn’t Have to Be “Either Or”
GENESYS gives users the best of both worlds by using CSDL as the core modeling language. You don’t have to worry about the esoteric jargon or complexity of SysML: GENESYS automatically generates SysML diagrams from the underlying CSDL model. This means you can easily meet the needs of stakeholders who expect SysML views, while continuing to provide clean, intuitive CSDL diagrams and views for those who simply want to understand the model content without being bogged down by esoteric terminology and notation. SysML becomes a helpful output, not a hurdle – just one of many tools in the systems engineer’s toolbox.
Conclusion: CSDL Is MBSE for the Modern Era
While SysML has played a foundational role in systems engineering, CSDL represents a leap forward – a modeling language designed for clarity, collaboration, and completeness. It’s not just a language for systems engineers; it’s a level playing field for everyone involved in building complex systems.
If your organization is ready to move beyond diagrams and embrace a truly integrated, stakeholder-friendly approach to MBSE, CSDL is the language to lead the way.
