MBSE Methodology, Digital Engineering Ecosystem & System Architecture Modelling using SysML v2

MBSE;Digital Engineering;System Engineering;Digital Engineering Ecosystem;Analysis;Trade Study;Requirements Verification;System Architecture Model;SAM;Model Based System Engineering;Integration;Automation

The presentation discusses and highlights an integrated digital engineering ecosystem to enable Model Based System Engineering (MBSE), as well as proposes a comprehensive MBSE Methodology supporting the same. Both MBSE Methodology and the digital engineering ecosystem enabling implementation of the methodology is showcased through a use case of antenna selection of a Digital Beamforming System for a UAV. Though the chosen use case is of an A&D background, but with complexity among various sectors like automotive, healthcare, etc. an integrated digital engineering ecosystem is the need of the hour. As known, the primary intent of MBSE is to allow early design decisions at conceptual stage itself. This can't be achieved just by system architecture modelling but requires one to analyse the system architecture model as well. The presentation discusses and showcases an MBSE Methodology and digital engineering ecosystem addressing the same as well as showcases as tool neutral framework allowing connection of SAM to various analysis tools integrated in a single & automated analytical workflow and perform Trade Study & Requirement Verification. It is also to be noted that the System Architecture Modelling is done using SysML v2 modelling language.

The presentation starts with an overview of MBSE Methodology. The MBSE Methodology has four pillars:
1st is Technical Management, i.e. to Support & Oversee System Engineering Process,
2nd is System Development i.e. to Virtually develop the system right from requirements to virtual validation,
3rd is Digital Engineering i.e. to Implement policies, processes & practices to build digital thread,
and lastly, there is System Architecture Analysis to perform all-round system analysis.
The presentation explains each of these in detail.

It is to be noted that there are dependencies between these pillars and involves concurrent co-dependent activities.

In particular, the use case highlights the 2nd-3rd & 4th pillars of system development (left side of V), digital engineering practices (creation of ASoTs) & Architecture Analysis for System Performance. The Digital Beamforming Use Case involves selection of phased array antennae design configuration of UAV communicating with a ground station, ship & a satellite. The design selection must ensure adequate link marking for communication between UAV & Ground station. MBSE Workflow is devised to verify system requirements and perform trade study for design selection.

The digital engineering environment involved in this MBSE workflow included SAM tool for system architecture modelling utilising SysML V2 modelling language, Mission Analysis Tool for scenario creation and setting up of Design Reference Mission, and Integration & Automation tool performing analysis, trade study and requirements verification. The MBSE the workflow starts with setting up of Design Reference Mission (DRM) first, & then System Architecture Model, followed by Analytical Workflow after which the Trade Study is performed.

The presentation highlights System Architecture Modelling using SysML V2:
> Creation of element definitions for the system parts to be used later in different views of requirements & structure diagrams.
> Model is organized into packages and necessary libraries needed to define the system attributes are imported.
> Within the organized package requirements and structure diagram is created showcasing the derivation and decomposition of system requirements. Constraints and attributes responsible for requirements satisfaction are defined within the requirements usages. Same can be marked with ‘satisfy’ relationship between part usage and requirement usage in the diagram.
> Within the structure diagram, decomposition of system into sub-systems is depicted through part usages having necessary system attributes inherited from definitions or defined anew within the usage.

Within SAM, we started with deriving system requirements based on DRM and decomposing it further in SWaP-C requirements. Parts responsible for requirement satisfaction were identified and part attributes were traced with ‘Satisfy’ relationship to the requirements. The system structure was completed with depiction of all the sub-systems and attributes applicable for the use case.

On completion of System Architecture Model, Analysis workflow was built-up to analyse the architecture. A multi-fidelity analysis workflow was developed to calculate the Measure of Effectiveness (MOEs) like Receiver’s signal strength, SNR, Weight, Size & Cost. The workflow constitutes both the low fidelity as well as the high-fidelity analysis, where in the antenna configurations are primarily varied through the an excel catalogue of commercial antenna designs. The low fidelity, non-DRM workflow utilized canonical equations defined within script components, whereas the high-fidelity, DRM workflow utilized the Mission Analysis Tool. This workflow is now connected with System Architecture Model.

SAM is connected to Analytical Workflow using an MBSE Connector. Analytical Workflow is added as analysis within MBSE Connector interface wherein the System Structure defined in SAM can be seamlessly connected to Analytical Workflow through linking of system’s part attributes to analytical workflow parameters. Similarly for requirements verification, a simple validation script can be added as an analysis within MC MBSE where in the requirements imported from SAM with MC MBSE can be linked with these validation script parameters. Bounds can be conveniently defined within connector interface or added into the scripts.

Now, with the connection established, a trade study can be initiated from within connector interface. A Design of Experiments (DOE) Study is launched from within connector, and various antenna configurations can be analysed by applying the constraints and objectives. Qualifying cases can be run individually to check requirement verification status and the selected designs can thereafter be saved and passed back to SAM while also updating the baseline values within the System Architecture Model hence, allowing for a complete traceability right from requirements definition to requirements verification and design selection.

The case illustrates benefits of MBSE Methodology & associated Digital Engineering ecosystem: early engagement of customers as well as SMEs in development lifecycle, ensuring continuous verification of customer needs and detection of faults errors in design.