MBSE - DE Ontology Handbook 2.0 v46

Table of Contents

Introduction
Overview
Position in Knowledge Hierarchy
Details
Practical applications and examples
- Implementing MBSE with IoIF
- Step-by-Step MBSE Workflow
Related wiki pages
References
Knowledge Graph
Associated Diagrams

Introduction

MBSE is a modern engineering approach that uses visual and mathematical models instead of documents to design, analyze, and verify complex systems. It helps engineers think through all system components and their interactions before physical implementation.

MBSE is not a tool or a specific methodology—it’s a paradigm that formalizes the use of modeling throughout the entire systems engineering lifecycle.

Overview

MBSE (Model-Based Systems Engineering) is 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 lifecycle phases. It’s a paradigm that encompasses many methodologies, tools, and languages.

MBSE fundamentally differs from traditional document-based systems engineering by creating a single, integrated model that serves as the authoritative source of truth for the system. This model supports multiple views for different stakeholders and can be used for analysis, simulation, and automated documentation.

MBSE is a key component of the Digital Engineering (DE) ecosystem, which integrates modeling, simulation, and data across the entire product lifecycle.

The MBSE paradigm has evolved to address the increasing complexity of modern systems, enabling better communication, reduced errors, and more efficient decision-making throughout the engineering process.

MBSE is not synonymous with SysML. While SysML is a common language used in MBSE, MBSE is the broader methodology that can use multiple modeling languages and tools.

Position in Knowledge Hierarchy

Broader concepts: - Digital Engineering (is-a)

Details

MBSE vs. MBE

MBSE and MBE (Model-Based Engineering) are related but distinct concepts within the broader Digital Engineering ecosystem:

Category	MBSE
Focus	System-level, cross-disciplinary
Primary Models	Descriptive models (structure, behavior, requirements)
Key Use Cases	System architecture, interfaces, requirements traceability
Typical Tools	SysML tools (MagicDraw, Cameo Systems Modeler)
Data Representation	Whole-part relationships, functional decomposition
Example	Catapult system architecture showing relationships between components
Category	MBE
Focus	Discipline-specific (mechanical, electrical, software)
Primary Models	Analysis and simulation models
Key Use Cases	Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD)
Typical Tools	ANSYS, MATLAB, Simulink
Data Representation	Mathematical relationships, physical properties
Example	Aerodynamic analysis of a catapult arm

MBSE Methodology and Tools

MBSE methodology involves creating a set of descriptive models that represent the system at various levels of abstraction. The most common modeling language for MBSE is SysML, which provides a comprehensive set of diagram types to represent system structure, behavior, and requirements.

The four pillars of SysML (used in MBSE) include:

Structure: Block Definition Diagrams (BDD) and Internal Block Diagrams (IBD)
Behavior: Activity Diagrams, State Machine Diagrams
Parametrics: Parametric Diagrams for mathematical relationships
Requirements: Requirements Diagrams for traceability

SysML v2 is nearing standardization by the Object Management Group (OMG) and is designed to better support the needs of MBSE workflows compared to SysML v1.

Creating MBSE Models

Creating effective MBSE models requires careful planning and adherence to best practices:

Start with a Concept of Operation (CONOP) to understand the operational context
Define system boundaries and key stakeholders
Create a Block Definition Diagram (BDD) to define system structure
Add Internal Block Diagrams (IBDs) to show component relationships
Define requirements and connect them to system elements
Use parametric diagrams for quantitative analysis

Use clear and descriptive names for your SysML blocks, properties, and OWL classes to ensure readability and maintainability.

Example: Catapult System Modeling

The Catapult case study demonstrates MBSE in action:

graph TD A[Catapult System] --> B[Block Definition Diagram] A --> C[Internal Block Diagram] A --> D[Parametric Diagram] B --> E[Catapult Arm] B --> F[Trigger Mechanism] B --> G[Target] C --> H[Catapult Arm Properties] C --> I[Trigger Mechanism Properties] D --> J[Range Calculation] D --> K[Impact Velocity] D --> L[Flight Time] J --> M[Parametric Equation] K --> M L --> M M --> N["Range = f(Initial Velocity, Launch Angle)"]

In the Catapult example, the MBSE model includes: - System structure (BDD showing components) - Component relationships (IBD) - Quantitative relationships (parametric diagram) - Mission objectives (range, impact velocity)

Practical applications and examples

Implementing MBSE with IoIF

The Armaments Interoperability and Integration Framework (IoIF) demonstrates how MBSE models integrate with semantic technologies:

Start with a SysML model of the system (e.g., Catapult)
Add an Assessment Flow Diagram (AFD) to define analysis relationships
Use stereotypes to align model elements with ontology classes
Configure IoIF with the SysML model and AFD
Run analysis workflows that connect different simulation tools

The IoIF framework leverages MBSE models to "configure" ontology-aligned data, hiding the complexity of ontologies from typical users.

Step-by-Step MBSE Workflow

Here’s a practical example of implementing MBSE using SysML and IoIF:

This example assumes you have SysML modeling tools (like Cameo Systems Modeler) and IoIF installed.

Create the System Model:
- Use a Block Definition Diagram (BDD) to define system components
- Example: Create a "Catapult" block with properties like "Max Range" and "Launch Angle"
Define the Analysis Flow:
- Create an Assessment Flow Diagram (AFD) showing relationships between parameters
- Example: Connect "Launch Angle" to "Range" using a parametric equation
Tag Model Elements with Ontology Classes:
- Apply stereotypes to model elements to indicate their ontology alignment
- Example: Add [CatapultSystem] stereotype to the Catapult block
Configure IoIF:
- Load the SysML model with the AFD into IoIF
- Configure the ontology alignment for the workflow
Run the Analysis:
- Execute the workflow using Jupyter Notebook or the Interactive Service Dashboard
- Analyze trade-offs between different design parameters

= Example Python code for IoIF workflow configuration
from ioif import IoIF

= Initialize IoIF with ontology configuration
ioif = IoIF(
    ontologies=["bfo.owl", "catapult_ontology.owl"],
    model_path="catapult_model.sysml"
)

= Configure the workflow with the AFD
ioif.configure_workflow(
    afd_path="catapult_afd.sysml",
    analysis_types=["Analysis as Designed", "Analysis as Manufactured"]
)

= Execute the workflow
results = ioif.run_workflow()

= Visualize results in the Decision Dashboard
ioif.visualize_results("Decision Dashboard")

The IoIF framework demonstrates how MBSE models serve as the "configuration" for semantic interoperability, allowing different tools to exchange data through ontology-aligned interfaces.

Related wiki pages

Digital Engineering
Ontology
SysML
IoIF
MBE
DE Ecosystem
Catapult Example

References

SysML v2 Documentation
Protégé Ontology Editor
Systems Engineering for the Digital Age: Practitioner Perspectives
Basic Formal Ontology (BFO)
OWL 2 Web Ontology Language
Systecon MBSE Resources

Knowledge Graph

Visualize the relationships between MBSE and related concepts

graph TD A[MBSE] --> B[SysML] A --> C[Descriptive Models] A --> D[Digital Engineering] B --> E[Structure] B --> F[Behavior] B --> G[Parametrics] B --> H[Requirements] C --> I[Block Definition Diagrams] C --> J[Internal Block Diagrams] D --> K[DE Ecosystem] D --> L[MBE] K --> M[IoIF] M --> N[Ontology-Aligned Data] N --> O[Semantic Web Technologies] O --> P[OWL] O --> Q[SPARQL] O --> R[Triplestores]

Associated Diagrams