Formal Performance Analysis and Simulation of UML/SysML Models for ESL Design

UML2 and SysML try to adopt techniques known from software development to systems engineering. However, the focus has been put on modeling aspects until now and quantitative performance analysis is not adequately taken into account in early design stages of the system. In this paper, we present our approach for formal and simulation based performance analysis of systems specified with UML2/SysML. The basis of our analysis approach is the detection of communication that synchronize the control flow of the corresponding instances of the system and make the relationship explicit. Using this knowledge, we are able to determine a global timing behavior and violations of this effected by preset constraints. Hence, it is also possible to detect potential conflicts on shared communication resources if a specification of the target architecture is given. With these information it is possible to evaluate system models at an early design stage

A model driven approach to analysis and synthesis of sequence diagrams

Software design is a vital phase in a software development life cycle as it creates a blueprint for the implementation of the software. It is crucial that software designs are error-free since any unresolved design-errors could lead to costly implementation errors. To minimize these errors, the software community adopted the concept of modelling from various other engineering disciplines. Modelling provides a platform to create and share abstract or conceptual representations of the software system – leading to various modelling languages, among them Unified Modelling Language (UML) and Petri Nets. While Petri Nets strong mathematical capability allows various formal analyses to be performed on the models, UMLs user-friendly nature presented a more appealing platform for system designers. Using Multi Paradigm Modelling, this thesis presents an approach where system designers may have the best of both worlds; SD2PN, a model transformation that maps UML Sequence Diagrams into Petri Nets allows system designers to perform modelling in UML while still using Petri Nets to perform the analysis. Multi Paradigm Modelling also provided a platform for a well-established theory in Petri Nets – synthesis to be adopted into Sequence Diagram as a method of putting-together different Sequence Diagrams based on a set of techniques and algorithms

Development Of A Cognitive Work Analysis Framework Tutorial Using Systems Modeling Language

At the present time, most systems engineers do not have access to cognitive work analysis information or training in terms they can understand. This may lead to a disregard of the cognitive aspect of system design. The impact of this issue is system requirements that do not account for the cognitive strengths and limitations of users. Systems engineers cannot design effective decision support systems without defining cognitive work requirements. In order to improve system requirements, integration of cognitive work requirements into the systems engineering process has to be improved. One option to address this gap is the development of a Cognitive Work Analysis (CWA) framework using Systems Modeling Language (SysML). The study had two phases. The first involved aligning the CWA terminology with the SysML to produce a CWA framework using SysML. The second was the creation of an instruction using SysML to inform systems engineers of the process of integrating cognitive work requirements into the systems engineering process. This methodology provides a structured framework to define, manage, organize, and model cognitive work requirements. Additionally, it provides a tool for systems engineers to use in system design which supports a user’s cognitive functions, such as situational awareness, problem solving, and decision making

An evaluation of OMG SysML 1.0a standard conformance between modelling tools

The SysML is a recent introduction to modelling languages for the systems engineering domain. Modelling tools are offering support for its notation. Studies related to the UML have indicated that modelling tools lack compliance to the UML language. This issue may apply equally to the SysML and the aim of this research is to investigate that language compliance issue. The first phase of this research is concerned with the compliance of current modelling tools to the SysML l.0a Final Adopted Specification (PAS). It consists of a comparative evaluation of candidate tools based on an ideal framework derived from the language specification. The second research phase consists of an interpretive evaluation. It is concerned with the ability of SysML modelling tools to consistently represent a modelling problem and this problem is derived from the language specification. This research may benefit future studies in the field of modelling tool evaluations, particularly studies on the effects of modelling tools with varying compliance to the SysML specification

Dependability modeling and evaluation – From AADL to stochastic Petri nets

Conduire des analyses de sûreté de fonctionnement conjointement avec d'autres analyses au niveau architectural permet à la fois de prédire les effets des décisions architecturales sur la sûreté de fonctionnement du système et de faire des compromis. Par conséquent, les industriels et les universitaires se concentrent sur la définition d'approches d'ingénierie guidées par des modèles (MDE) et sur l'intégration de diverses analyses dans le processus de développement. AADL (Architecture Analysis and Design Language) a prouvé son aptitude pour la modélisation d'architectures et ce langage est actuellement jugé efficace par les industriels dans de telles approches. Notre contribution est un cadre de modélisation permettant la génération de modèles analytiques de sûreté de fonctionnement à partir de modèles AADL dans l‘objectif de faciliter l'évaluation de mesures de sûreté de fonctionnement comme la fiabilité et la disponibilité. Nous proposons une approche itérative de modélisation. Dans ce contexte, nous fournissons un ensemble de sous-modèles génériques réutilisables pour des architectures tolérantes aux fautes. Le modèle AADL de sûreté de fonctionnement est transformé en un RdPSG (Réseau de Petri Stochastique Généralisé) en appliquant des règles de transformation de modèle. Nous avons implémenté un outil de transformation automatique. Le RdPSG résultant peut être traité par des outils existants pour obtenir des mesures de sûreté de fonctionnement. L'approche est illustrée sur un ensemble du Système Informatique Français de Contrôle de Trafic Aérien. ABSTRACT : Performing dependability evaluation along with other analyses at architectural level allows both predicting the effects of architectural decisions on the dependability of a system and making tradeoffs. Thus, both industry and academia focus on defining model driven engineering (MDE) approaches and on integrating several analyses in the development process. AADL (Architecture Analysis and Design Language) has proved to be efficient for architectural modeling and is considered by industry in the context presented above. Our contribution is a modeling framework allowing the generation of dependability-oriented analytical models from AADL models, to facilitate the evaluation of dependability measures, such as reliability or availability. We propose an iterative approach for system dependability modeling using AADL. In this context, we also provide a set of reusable modeling patterns for fault tolerant architectures. The AADL dependability model is transformed into a GSPN (Generalized Stochastic Petri Net) by applying model transformation rules. We have implemented an automatic model transformation tool. The resulting GSPN can be processed by existing tools to obtain dependability measures. The modeling approach is illustrated on a subsystem of the French Air trafic Control System