Model-Based Systems Engineering Process Research Articles

A methodology for developing SoS architectures using SysML model federation

AbstractAn essential role of systems engineering is to aid in overcoming complexity during development. As system complexity increases, a greater number of organizations are being asked to contribute architecture/design content for systems development. An essential challenge to overcome is how to ensure digital continuity in connecting system models to form systems of systems (SoS) models. Leveraging recent developments in digital engineering (DE) and model‐based systems engineering (MBSE) this paper presents a SysML model federation methodology enabling multiple collaborating organizations to contribute system models and form a descriptive SoS architecture model. Systems engineers applying this methodology are able to reuse constituent system model content to describe the larger SoS behavior and structure while promoting reusability and commonality and are therefore better able to ensure correctness and consistency across development. First, a background through the review of SoS engineering (SoSE) and DE/MBSE literature is provided. Then an MBSE process along with specific methods tailoring the use of SysML within the Cameo Enterprise Architecture tool is presented. This work builds upon a previously published Systems Architecture Model (SAM) development method and is designed to permit style diversity across peer constituent models and ensure that every piece of data has an authoritative source of truth (ASOT) within the federation. This paper then presents the application of this methodology to the Ranger Lunar Rover system by making use of its openly published SysML model. Finally, the benefits and challenges of this methodology are discussed prior to drawing closing conclusions and identifying future areas of research.

Event-based safety and reliability analysis integration in model-based space mission design

Model-based safety and reliability (S&R) analysis, which improves analysis accuracy and reduces cost and development time is applied in various industries. With the developments in model-based systems engineering (MBSE) and the use of systems modelling language (SysML), S&R analysis based on SysML models is gaining more attention. However, the emerging methods are inadequate for complex space missions. Thus, the main objective of this study involves integrating S&R analysis in SysML-based space mission design. First, a framework for integrating S&R analysis in model-based space mission design is presented. Based on the characteristics of the development of complex space missions and the MBSE process, a multisystem collaborative failure analysis method is proposed to comprehensively identify the failure modes (FMs) of the entire system. Subsequently, an event-based analysis method integrating the process of functional architecture definition is proposed, which fills the identified gaps in model-based S&R analysis for mission-level systems. Based on the identified FMs and proposed criterion, the event tree can be mapped from the SysML activity diagram. Finally, the proposed methodology is applied to a case study of a complex space mission in the near future: the manned mission to the Moon.

Operationalizing digital twins through model‐based systems engineering methods

AbstractIn recent years there has been increased demand for readiness and availability metrics across many industries and especially in national defense to enable data‐driven decision making at all levels of planning, maintenance, and operations, and in leveraging integrated models that inform stakeholders of current operational system health and performance metrics. The digital twin (DT) has been identified as a promising approach for deploying these models to fielded systems although several challenges exist in wide adoption and implementation. Two challenges examined in this article are that the nature of DT development is a system‐specific endeavor, and the development is usually an additional effort that begins after initial system fielding. A fundamental challenge with DT development, which sets it apart from traditional models, is the DT itself is treated as a separate system, and therefore the physical asset/DT construct becomes a system‐of‐systems problem. This article explores how objectives in DT development align with those of model‐based systems engineering (MBSE), and how the MBSE process can answer questions necessary to define the DT. The key benefits to the approach are leveraging work already being performed during system synthesis and DT development is pushed earlier in a system's lifecycle. This article contributes to the definition and development processes for DTs by proposing a DT development model and path, a method for scoping and defining requirements for a DT, and an approach to integrate DT and system development. An example case study of a Naval unmanned system is presented to illustrate the contributions.

A model-driven framework for design and verification of embedded systems through SystemVerilog

The demands of system complexity and design productivity for embedded systems can be managed by simplifying and reusing the design. Furthermore, these systems should be verified as early as possible in the development process to reduce the cost and effort. The rationale of the proposed framework in this article is to simplify the design and verification process of embedded systems in the context of Model Based System Engineering (MBSE). To achieve this, UML profile for SystemVerilog (UMLSV) is proposed to model the design and verification requirements. Particularly, we introduce various UMLSV stereotypes to model the system design (structure and behavior). Furthermore, a temporal extension of Object Constraint Language is used to capture the verification requirements (properties/constraints) in UMLSV. Consequently, the proposed framework allows the modeling of system design (structure and behavior) along with the verification aspects at higher abstraction level. Following the MBSE process, the high-level models and the verification constraints are transformed into synthesizable SystemVerilog Register Transfer Level and SystemVerilog Assertions code. This leads to perform the Assertions Based Verification of system design in the early development phases by using state-of-the-art simulators. The effectiveness of the proposed framework is demonstrated with the help of multiple case studies including Traffic Lights Controller, Unmanned Aerial Vehicle, Elevator and Car Collision Avoidance System.

Implementation of Human System Integration (HSI) and ‘Non-functional Characteristics’ into the Systems Engineering Lifecycle - A Practical Approach at Airbus Defence and Space

This paper provides an overview of the process, practices, developments and synergies that Airbus Defence and Space are implementing Human System Integration (HSI) into the Continuous Engineering /Model Based System Engineering (MBSE) throughout the company. The paper highlights these developments, which include internal research programmes, European Union funded research projects, Airbus internal Synergy project. This research includes an EU funded 3 year project HoliDes - Holistic Human Factors and System Design of Adaptive Cooperative Human Machine Systems. Continuous engineering within Airbus has included various corporate and divisional Synergy programs and lean and agile initiatives. As our business is defined by Multiple Portfolio products, supplied from multi countries, the MBSE process had to speed up delivery and reduce overall cost. The Airbus process models needed significant amendment due to products supplied via multiple business lines throughout the company. This problem is exacerbated by varying requirements of four national defence requirements, who impose restrictions on the use of Architectural Frameworks (NAF/MODAF/DODAF) and supporting tools. Our Human System Integration (HSI) is continuing from the initial Human View Architectural Framework research to include the nine HSI domains. These nine domains overlap with our current Human factors research and will now allow us to pull in our Non-functional work into our Systems Engineering lifecycle. This paper highlights the research projects Airbus Space and Defence are incorporating in to our overall strategy, these include internal R&D funding and European Union funded research programs. These research projects have highlighted several areas of interest these include, stochastic modelling with respect to Human System Integration and Human views, verification and analysis of emergent behaviour and non-functional properties, which conforms with our own work on non-functional requirements and finally the use of System of System Formal Methods for parts of the lifecycle.

An Analysis of the Model Based Systems Engineering Process

AbstractMuch of systems engineering has been performed by writing requirements and specifications primarily in text. An alternative approach preserves the proven best practices of systems engineering, but adds rigorous computer executable models to capture and record the information which describes the system. The requirements and specifications are executable and transformable. Text descriptions are joined to the models so that the proven best practices are not replaced; they are augmented.This paper analyzes the systems engineering process using executable models of behavior and executable models of structure. The structure models are compatible with the traditions of mechanical engineering, electrical engineering and modern object‐oriented software.A major goal of this work is to provide a convenient separation of the concerns of the systems engineer and to use abstraction to make the sub‐processes as simple as possible.