Contracts and Behavioral Patterns for SoS: The EU IP DANSE approach

This paper presents some of the results of the first year of DANSE, one of the first EU IP projects dedicated to SoS. Concretely, we offer a tool chain that allows to specify SoS and SoS requirements at high level, and analyse them using powerful toolsets coming from the formal verification area. At the high level, we use UPDM, the system model provided by the british army as well as a new type of contract based on behavioral patterns. At low level, we rely on a powerful simulation toolset combined with recent advances from the area of statistical model checking. The approach has been applied to a case study developed at EADS Innovation Works.Comment: In Proceedings AiSoS 2013, arXiv:1311.319

Understanding the Elements of Executable Architectures Through a Multi-Dimensional Analysis Framework

The objective of this dissertation study is to conduct a holistic investigation into the elements of executable architectures. Current research in the field of Executable Architectures has provided valuable solution-specific demonstrations and has also shown the value derived from such an endeavor. However, a common theory underlying their applications has been missing. This dissertation develops and explores a method for holistically developing an Executable Architecture Specification (EAS), i.e., a meta-model containing both semantic and syntactic information, using a conceptual framework for guiding data coding, analysis, and validation. Utilization of this method resulted in the description of the elements of executable architecture in terms of a set of nine information interrogatives: an executable architecture information ontology. Once the detail-rich EAS was constructed with this ontology, it became possible to define the potential elements of executable architecture through an intermediate level meta-model. The intermediate level meta-model was further refined into an interrogative level meta-model using only the nine information interrogatives, at a very high level of abstraction

Integrating life cycle assessment in model-based systems engineering

The emergence of smart products has led to the development of an increasing number of multidisciplinary systems. For the successful development of such systems, a holistic approach is necessary, such as model-based systems engineering (MBSE). It is argued that certain product development activities could be integrated and improved with MBSE, one such activity being the assessment of environmental impacts. This article presents a case study on the usage of Life Cycle Assessment (LCA) on a MBSE system model. In the study a technical system is modelled with views according to the MagicGRID approach. The scope and goal of the LCA are defined by using SysML diagrams and elements. Additionally, different system variants are modelled to explore the capability of comparing LCA studies. At the end of the case study, the benefits, limitations, and shortcomings of the integration are discussed

Digital Twin: towards the integration between System Design and RAMS assessment through the Model–Based Systems Engineering

The design of a safety-critical system requires an effective prediction of its reliability, availability, maintainability and safety (RAMS). Anticipating the RAMS analysis at the concept design helps the designer in the trade-off of the system architecture and technologies, reduces cost of product development and the time to market. This action is rather difficult, because the RAMS analysis deals with the hazard assessment of system components, whose abstraction at concept level is never simple. Therefore, to integrate the system design and RAMS assessment, a clear path to follow is required. The paper investigates how the Model Based Systems Engineering (MBSE) supports this task and drives the system reliability allocation, through the functional and dysfunctional analyses. The implementation of the proposed approach needs to set up the tool chain. In the industrial context it must be compatible with practices, standards and tools currently used in product development. Defining a suitable process of integration of tools used for the System Design and the Safety Engineering is a need of industry. Therefore, this task is also discussed, in this paper, dealing with some examples of industrial test case

A Framework for Executable Systems Modeling

Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation. In response to these challenges, a number of auxiliary standards have been offered by the Object Management Group (OMG); most pertinent here are the foundational UML subset (fUML), Action language for fUML (Alf), and the UML profile for Modeling and Analysis of Real Time and Embedded Systems (MARTE). However, there remains a lack of a similar treatment of SysML tailored towards precise and formal modeling in the systems engineering domain. This work addresses this gap by offering refined semantics for SysML akin to fUML and MARTE standards, aimed at primarily supporting the development of time based simulation models typically applied for model verification and validation in systems engineering. The result of this work offers an Executable Systems Modeling Language (ESysML) and a prototype modeling tool that serves as an implementation test bed for the ESysML language. Additionally a model development process is offered to guide user appropriation of the provided framework for model building

Modellability of System Characteristics - Using Formal Mark-up Languages for Change Capability by Design

AbstractChange capability enables a production system to cope with external influences in an efficient, fast and self-organized manner. Several approaches have been designed for measuring change capability by specific indicators which represent core characteristics of production systems. On the other hand, formal modelling languages are used for production system design. Unfortunately, these languages do not match with system characteristics and especially with those indicators of change capability. Due to this missing linkage, existent production system models don’t facilitate the implementation of a system's change capability by design. Goal of this contribution is to point out the possibilities of operationalization approaches and their potential to be extended for (formal) modelling of system characteristics and sub properties, exemplified by using the concept of change capability. Additionally, the potential of change capability to be representable in a formal language will be exemplarily outlined by emphasizing on Systems Modelling Language (SysML). For this purpose, a qualitative approach with an emphasis on literature- and content analysis will be applied. Results of this contribution are (1) to pinpoint the research gap (which is also of crucial practical relevance) and (2) to point out possible solution approaches for a formal modellability of system characteristics

Cost optimization in requirements management for space systems

2021 Spring.Includes bibliographical references.When producing complex space systems, the transformation of customer needs into a realized system includes the development of product requirements. The ability to generate and manage the requirements can either enable the overall system development or drive significant cost and schedule impacts. Assessing practices in the industry and publications, it is observed that there is a substantial amount of documented approaches to address requirement development and product verification, but only a limited amount of documented approaches for requirements management. A complex system can have tens of thousands of requirements across multiple levels of development which, if not well managed, can lead to hidden costs associated with missed requirements and product rework. With current space system projects being developed at a rapid pace using more cost constrained approaches such as fixed budgets, an investigation into more efficient processes, such as requirements management, can yield methods to enable successful, cost effective system development. To address the optimal approach of managing requirements for complex space systems, this dissertation assesses current practices for requirements management, evaluates various contributing factors towards optimization of project costs associated with this activity, and proposes an optimized requirements management process to utilize during the development of space systems. Four key areas of process control are identified for requirements management optimization on a project, including utilization of a data focused requirements management approach, development (and review) of requirements using a collaborative software application, ensuring the requirement set is a consolidated with an appropriate amount of requirements for the project, and evaluating when to officially levy requirements on the product developers based on requirement maturation stability. Multiple case studies are presented to evaluate if the proposed requirements management process yields improvement over traditional approaches, including a simulation of the current state and proposed requirements management approaches. Ultimately, usage of the proposed optimized set of processes is demonstrated to be a cost effective approach when compared against traditional processes that may adversely impact the development of new space systems

Multidomain Simulation Model for Analysis of Geometric Variation and Productivity in Multi-Stage Assembly Systems

Nowadays, the new era of industry 4.0 is forcing manufacturers to develop models and methods for managing the geometric variation of a final product in complex manufacturing environments, such as multistage manufacturing systems. The stream of variation model has been successfully applied to manage product geometric variation in these systems, but there is a lack of research studying its application together with the material and order flow in the system. In this work, which is focused on the production quality paradigm in a model-based system engineering context, a digital prototype is proposed to integrate productivity and part quality based on the stream of variation analysis in multistage assembly systems. The prototype was modelled and simulated with OpenModelica tool exploiting the Modelica language capabilities for multidomain simulations and its synergy with SysML. A case study is presented to validate the potential applicability of the approach. The proposed model and the results show a promising potential for future developments aligned with the production quality paradigm