This article shares an overview of a Model-Based Systems Engineering initiative.
Model-Based System Engineering (MBSE) is a system engineering initiative to create a digital model of a system that is used by all engineering disciplines and other functional organizations within a company. An MBSE model can also be used to simulate the system’s performance in a similar fashion to Model-Based Development.
Components of an MBSE Model
MBSE models represent flowchart diagrams, often developed with System Modeling Language (SysML). The blocks within the diagrams represent a range of different types of information:
- Requirements: Represents the traits, characteristics or performance demands that the system must satisfy.
- Functions: Generic definition of the capabilities that the system must provide in order to fulfill requirements.
- Items: Hardware and software items that enable functions. In some cases, an MBSE model can be integrated with discipline-specific models such as those from Mechanical Computer-Aided Design (MCAD), Mechanical Computer-Aided Engineering (MCAE), Electrical Computer-Aided Design (ECAD) and Integrated Development Environments.
The connections between these blocks represent different relationships.
- Requirements Allocated to Functions: Represents that a requirement will be fulfilled by a specific function.
- Functions Allocated to Items: Represents that a specific item will enable a specific function.
Why Pursue a Model-Based Enterprise Initiative?
There are a few reasons an organization would pursue this initiative, including:
- Clear Communications between Engineering Disciplines: Traditionally, systems have been defined using multiple documents, spreadsheets, and presentations. The primary issue with this approach is propagating change and misinterpretation amongst those definitions, leading to delays and errors in the development process. Having a single definition for the system shared amongst all parties removes ambiguity and confusion.
- Traceability of Change: During the development process, engineers perform trade studies to explore and assess different possible design alternatives. In MBSE models, where relationships are clearly defined, an engineer can understand which things will be affected by a change. For example, one can see which functions are related to a requirement and which items are related to those functions. Alternatively, one can see which functions are related to which items and which requirements are related to those functions. This provides clarity in understanding the impact of a design change.