Why MBSE and SysML?
Sandy Friedenthal, one of the leaders of the effort to develop SysML, talks about MBSE (Model-Based Systems Engineering) and SysML, in an interview with Kenji Hiranabe, CTO of Change Vision (the maker of Astah).
Video Transcript
Kenji: Today I am with Sandy Friedenthal, an independent consultant in MBSE (Model-Based Systems Engineering). He previously worked at Lockheed Martin, a large aerospace corporation, where he was responsible for advancing the practice of model-based systems engineering across the company.
He was a leader of the effort to develop the OMG Systems Modeling Language (SysML), and is co-author of “A Practical Guide to SysML”. He is also co-chair of the INCOSE Model-Based Systems Engineering Initiative.
How does model-based systems engineering relate to systems engineering?
Sandy: Systems engineering (SE) is a multi-disciplinary approach to ensure that the pieces of a system work together to achieve the objectives of the whole. Each engineering discipline, such as software, mechanical and electrical engineering, focuses on its discipline-specific aspects of the system, whereas SE addresses the aspects that span the other disciplines and subsystems, to ensure a balanced system solution that meets the customer’s needs.
Model-based systems engineering (MBSE) is systems engineering with models. The system models are a primary artifact that is managed and controlled throughout the development process. Although there are many different kinds of models, the emphasis is on the system architecture model, which helps integrate the various aspects of the system.
Why MBSE?
Sandy: MBSE is often contrasted with more traditional, document-based approaches to systems engineering.
In a document-based approach, systems engineering data is usually held in traditional documents such as text specifications, spreadsheets and PowerPoint slides. Information about the system requirements and high-level design is spread across many different documents, which makes it difficult to maintain and keep consistent. In MBSE, the same information is captured more formally in a system model, which makes it more consistent, traceable and precise.
How does SysML relate to MBSE?
Sandy: SysML is a graphical modeling language, and a key enabler of MBSE. It is sometimes called a descriptive modeling language, used to describe multiple views of the system architecture. This contrasts with analytical models, such as Simulink models, or geometric models used in CAD. However, the architecture model is intended to be integrated with other analytical and geometric models, typically through third-party plug-ins in a system modeling tool.
What are the essential aspects of an MBSE approach?
Sandy: A practitioner of MBSE must learn the modeling language, the modeling tool and the MBSE method used to perform systems engineering. This, of course, comes on top of the domain-specific knowledge required for the system being designed.
An organization that wants to adopt MBSE must develop the infrastructure, including tools, methods and training, and provide skilled people, tools and processes to its projects so they can implement MBSE.
How to start MBSE?
Sandy: There are a few essentials to get started. First, an organization needs a sponsor and a technical advocate who can lead the initiative. It is often an advantage to integrate this effort with other existing improvement initiatives, where that makes sense.
As a starting point, it is important to understand the current practice and the systemic issues that MBSE may be able to address, and to clearly determine and document why you are adopting MBSE in your organization.
The key stakeholders should then develop a strategy and plan for their MBSE approach to address these issues. The plan includes the activities to develop the infrastructure incrementally and deploy this capability to projects. The results should be evaluated as a basis for continuous improvement.
To start modeling with SysML, see Astah SysML and the Quick SysML Tutorial.