All features supporting the SysML v2 BETA specification are currently ALPHA and subject to change. The final SysML 2.0.0 specification is expected to be officially adopted in the second half of 2025. While there have been many questions during the finalization, we believe this implementation provides enough value for early adopters to start preparing to create and execute models using the new specification. We will be expanding support for the specification through finalization, into SysML v2.1, and beyond. There are a small number of remaining issues related to execution scheduled for revision in SysMLv2.1. We will be expanding and clarifying support for SysML v2.x throughout the upcoming language revision process. Consult the What's New and Modeling with SysML v2 pages for more information about what is currently supported.
Behavior Execution Engine SysML v2 Tutorials
Overview
Behavior Execution Engine is a capability through which you can execute modeled architectures with SysML. Creating executable architecture fundamentally forces you to rethink how to describe systems and their behaviors. When you design system representations, you need to understand how those systems and subsystems interact so you can gain a clear conception of how your systems behave during operation. You need to understand not only how to design the physical systems that satisfy the programmatic requirements, but also how to represent the system behaviors so that you can execute and simulate them directly from the same models that describe the system. Modeling with execution in mind can often lead to early insights into design issues for digital system representations prior to operating the real systems in their real operational environments.
Before you start, ensure your computer meets the minimum required specifications listed in the Installation Guide. Make sure you have access to the System Architecture Modeler and have installed the Behavior Execution Engine with the proper licensing.
Each of these tutorials is also broken up into several sections that focus on specific topics. Each tutorial builds on the preceding tutorial, and each section builds on the preceding section, with the complexity increasing as you progress. You can walk through the tutorials from start to finish, or customize your learning experience and skip around, as each section specifies the prerequisite SysML v2 project file (.sysml) that you will need from the Behavior Execution Engine installation in order to get started.
Thank you for choosing Behavior Execution Engine, and please be sure to reach out if you have any questions or feedback for our team.
The Tortoise and the Hare Tutorial
To understand the thought process and mechanisms through which you can create and then execute a SysML v2 model, you are going to construct a model for the infamous race between the Tortoise and the Hare from Aesop’s Fables. This provides a mechanism to discuss and demonstrate the process through which the Behavior Execution Engine can:
- Facilitate the simulation of dynamically evolving systems
- Enact interactions between these systems
- Measure the effectiveness of operating the systems in their intended use cases
You are going to explore two approaches to modeling the race.
The first will be a simplified discrete-timestep-based approach, something most engineers should recognize. You will use a heartbeat mechanism to move the simulation forward at a fixed cadence. With this approach, Behavior Execution Engine will evaluate events, provide comparisons, and drive transitions at the precision of the check in rate you defined.
The second approach will utilize features of Behavior Execution Engine to perform continuous event detection as a continuous function of time. In this approach, the transitions will traverse at precisely computed time instants as opposed to the fixed cadence timestep. Through both approaches, Behavior Execution Engine will handle the simulation execution: controlling the time progression, event finding, math operations, and comparisons between the instances in the simulation.