System Architecture has a primary role in communication between stakeholders, in addition to planning and structuring the whole architectural process. Architecture Description Languages (ADLs) should be helping within architectural activities. However, most ADLs have not yet been widely used in industry. Another limiting factor for the effective use of ADLs is the difficulty of these languages in concretely expressing complex systems architecture. Considering this situation for the effective use of ADLs, UML has been often used in past years for architecture modeling. However, UML itself presents difficulties in representing characteristics which are pertinent to real-time systems, such as security or real-time restrictions. One of the advantages of UML is its extensibility, ability which allows creation of profiles. Thus, this work presents the Systems Modeling Language (SysML), a UML profile used for system architecture modeling. SysML and Architecture Analysis & Design Language (AADL) languages were both applied to a case and compared. As a conclusion, it was noticed that SysML is better than AADL when modeling abstract characteristics, such as decision making and loops functionality, which are not well-described in AADL.

The development of Real-Time Embedded Systems (RTES) considering critical and volatile system and software requirements is a difficult and error-prone activity. The capability to describe system components while highlighting and maintaining their correlations at different abstraction levels and refinements has a significant impact on RTES development. Most techniques for designing RTES present many problems and limitations regarding tracing RTES constraints along of architectural design. Moreover, there is a gap in integrated strategies to evaluate the correctness of these constraints from model specification to the system models realization. This article aims to perform a study on Model-Driven Systems Engineering approaches applied in the design and traceability of specific RTES constraints. The main objective of this study is to automatically perform an evaluation of traced non-functional concerns and provide feedback to the developers regarding the validity of the simulated constraints. In order to achieve this objective, this study, initially, develops a formalized manner to specify RTES constraints in architectural viewpoints and a tool to evaluate the real simulated values of these specifications.

Zusammenfassung Eine Systemarchitektur sollte die entsprechenden Funktionen, Dienste und Einschränkungen des Systems unter verschiedenen und verständlichen Beschreibungen darstellen. In dieser Arbeit werden Strategien für Architekturentwurfe vorgestellt und für Echtzeit- und Eingebettete Systeme (RTES) analysiert. In diesem Artikel präsentieren wir ein praktisches Entwurfsmodell einer Architektur für Automobilsysteme anhand von sogenannten Entwurfs-Sichtweisen. Modelle werden in den operativen, funktionalen, logischen und technischen Sichtweisen eines Systems betrachtet und können bei frühen Entwurfsbeschreibungen mehrere funktionale und nicht funktionale Eigenschaften von RTES darstellen. Der vorgeschlagene Ansatz wird in einer industriellen Fallstudie im Automobilbereich evaluiert. Zusätzlich zur Definition der Sichtweisen stellt diese Untersuchung einen spezifischen Rahmen für die RTES-Entwicklung vor. Diese Strategie des Entwurfs kann die Eigenschaften der RTES hervorheben und das System auf verschiedenen Abstraktionsebenen beschreiben. Darüber hinaus wird durch Experteninterviews aus den jeweiligen Systementwurfsdomänen eine Qualitative Bewertung vorgenommen, um zu analysieren, ob die Modelle der entsprechenden Sichtweisen das erwartete und gewünschte Systemverhalten repräsentieren.

The initial desire for accomplishing this research grew from a family dream.A dream that was not mine, but one that came to sculpture and be the sculptor of the person I would become.In all certainty, looking back over my expectations some four years ago, I never imagined that study and qualification would fuse into my persona in such a dignifying manner.The student, professor, researcher and the very human being of four years ago are no longer the same.The contributions presented in this thesis are the result of four years of dedication, resilience and love for research.Indeed, it also comes from the help, support, comprehension, dedication and fidelity of the innumerous individuals involved.To my almighty Lord, thank you for giving me health and strength to continue and for supporting me throughout.I was fortunate to have the privilege of counting on the contribution of three su-

The specification, analysis and design of real-time systems (RTS) are activities that arc highly dependent on an effective understanding of the application domain and on the thorough representation of their basic requirements. The use of model-based approaches for the development of RTS systems tends to contribute to minimizing the complexity of the system development UML has been used intensely in recent rears for modeling requirements of real-time software. However, UML alone does not completely represent the important features associated with these systems. UML is a language that has several extension capabilities enabling the creation of specific profiles. This article will explore the use of UML profiles SysML and MARTE for the modeling of RTS software requirements. with its main area of application being the control of urban traffic. The main objective is to demonstrate the application of SysML with MARTE stereotypes, which enables the modeling and tracing of individual software requirements.

Architectural design of Real-Time and Embedded Systems must describe the system components (software and hardware) in a common and comprehensible manner to be understandable to several stakeholders involved in the development process. This article explores the combined adoption of a well-recognized methodology to activities of architectural system design, with the MARTE profile, considering non-functional annotations in model elements. The proposed approach aims to define a general and appropriate architectural viewpoint to the real-time and embedded domain. MARTE profile and SPES methodology are employed in modeling strategies in order to explore the requirements, services and systems components. In this paper, a case study in the automotive system domain is performed and the architectural viewpoints are able to represent functional and non-functional requirements, performance and temporal restrictions in the field of automotive systems at different levels of detail and abstraction.

Development of Real-Time Embedded Systems (RTES) is currently a great challenge, as industry has to coherently model, develop and evaluate functional and non-functional requirements of these systems. Several approaches to RTES specification and design have been proposed in past years, but they most often fail to support early timing representation and, also, for advanced evaluation of timing constraints. Furthermore, not all of these approaches describe non-functional constraints in all viewpoints, models and refinements along the system design process. This research aims to identify and model real-time and embedded constraints in system design artifacts and, also, to refine and trace them along of architectural viewpoints. MARTE constraints have been consistently applied in design models and implemented at lower abstraction models. Here, timing constraints generation are performed from the graphical models to the final code models. Additionally, a case study in the automotive domain has been proposed in order to check the imposed timing constraints regarding specification of architectural models.

When developing Real-Time and Embedded Systems (RTES), different types of constraints should be considered in specification, modeling, architectural design and system implementation. In most cases, these constraints describe timing, precedence or resource restriction. Correct description and evaluation of these complex information along of RTES design are directly related to their reliability, safety and quality. In this research, a methodology to describe real-time and embedded information in requirements, functional, logical and technical viewpoints is briefly presented, as well as an approach to analyze the annotated constraints. MARTE constraints have been consistently applied in designing models and implemented at lower abstraction models. Here, pseudo automated generation of timing, precedence and resources constraints is performed from the graphical models to the final source code models. Therefore, the proposed approach has a great value to RTES design once it has traced constraints along of the architectural design and it also presents a manner to check if constraints are being reached in accordance with early design description.

The Digital Twin is one of the most important concepts in the Cyber Physical Systems (CPS) era. It can bring benefits such as simulation, monitoring or management once it joins the physical and the virtual through the Internet of Things. This concept is being adopted more and more in the academia and in the industry, but there is still a lack of methods to define and formalize the representation of the Digital Twin, as for example semantic models. Ontologies are a way of representing knowledge that can be shared between different entities, allowing a common understanding about a information. In this sense, this work proposes an ontology to represent Digital Twin in the context of CPS and embedded systems. These concepts are implemented through a proposed architecture. The proposed ideas are being evaluated with industrial case studies and some of the preliminary results are described in the paper.

Adoption of semantic technologies in the context of automation systems is growing. Semantic technologies can contribute and intensify the machine-to-machine communication, and it has been allowing each time more the collaboration between human and machines. In this sense, semantic technologies have been contributing to adoption of Cyber Physical Systems in the Industry 4.0. In this context, there are plenty of data being generated that has to be integrated between the system components. However, it is important to provide a manner to integrate these objects in an easy and understandable way for the users. This paper presents how it is possible to map industrial elements into a semantic model in order to support services and, also, to allow the communication of these elements with the physical/real system through an IoT middleware. For this proposal, an ontology has been developed as well as an extension of a consolidate IoT middleware to support using these models. The proposed ideas are being evaluated with some industrial case studies and some of the preliminary results are described in the paper.

System architecture should describe the functions, services and constraints of the system under different and intelligible descriptions. In this research, strategies for architectural design are presented and analysed for Real-Time and Embedded Systems (RTES). More specifically, within this paper we present a convenient design model of an architecture for automotive systems through viewpoints of design. Models are considered at the operational, functional, logical and technical views of a system and they are able to represent, at early design descriptions, several functional and non-functional properties of RTES. The proposed approach is adopted in an industrial case study in the automotive domain. In addition to the viewpoints definition, this research presents a specific framework for RTES development. This strategy of design can highlight the properties of the RTES while describing the system in different abstraction levels. In addition, the strategy of research is qualitatively evaluated through interviews with experts of the domain in order to analyse if the viewpoints are representing the expected and desired system behavior.

Development of Real-Time and Embedded Systems (RTES) involves a number of complex activities performed by a diversity of stakeholders. In most cases, RTES requires a number of different physical and logical components with numerous functional and non-functional constraints. Therefore, it is essential to ensure the representation, specification and analysis of quality activities of these systems since the early design activities. SPES (Software Platform Embedded Systems) methodology has been considered to describe a framework to develop RTES, but it does not specify directly how and which modeling languages should be adopted. Thus, this research adopts SPES guidelines and applies SysML and MARTE profiles to create models in the architectural viewpoints, while it highlights functional properties and different non-functional constraints of the system. A formalization of design viewpoints is presented in order to contribute to quantitative measurement to describe an analysis of the design complexity since the initial design activities. As contributions of this paper, it can be highlighted a proposal to formalize the RTES design activities (viewpoints), a measurement of the system design complexity since the initial design activities (in accordance with the design activities) and, also, the definition of a formalized manner to analyse RTES complexity without the interference of user external knowledge.

Activities for the comprehension and development of Cyber-Physical Systems (CPS) include analysis of multiple disciplines including mechanical engineering, electronic engineering, systems engineering and computer science. This work presents a comprehensive and applicable methodology for the initial activities of the development process of CPS. This methodology displays the capacity to describe and enable detailed analysis of the relevant properties of these systems as, for example, time specification, resources, communication and non-functional properties of CPS. In this research, two consolidated approaches of Model-Based Engineering are used in a combined way for proposing a methodology for requirements analysis, modeling and formal specification of CPS. Initially, a strategy for the definition, modeling, specification, and categorization of requirements in a tabular way is proposed. From the system definition in a high abstraction level, the SysML Requirements diagram is extended by using UML profile MARTE/VSL for formalization of restrictions, annotations and stereotypes in the model. Initial results of the application of the proposed methodology are presented by means of a case study of the Industrial Packing System.

The UML profile for Modeling and Analysis of RealTime and Embedded Systems (MARTE) describes semantics and syntax for designing embedded and real-time systems, providing capabilities for representing the intrinsic characteristics of these systems, such as resource allocation, time criteria, non-functional characteristics, among others. MARTE provides different constructors and appropriate annotations for design activities allowing representation of quantitative characteristics that are relevant to the domain of a real-time system such as, for example, deadlines, periods, processing capacity, timing, and also qualitative characteristics that relate to system performance, including methods of communication and concurrence. This paper presents an in-depth study about the CoreElements, Time and GRM packages of the MARTE profile. In addition, it presents an initial analysis of conformity of MARTE constructors in the context of the specification processes and design of automotive systems. It is important to emphasize that the presented models are strengthened with MARTE constructors,by allowing the representation of functional and non-functional requirements, performance and temporal restrictions in the field of automotive systems already in initial stages of system design.

Real-time and embedded systems (RTES) encompass a variety of embedded and real-time properties and requirements which defines them. Timing behavior of RTES physical and logical subsystems is as important as their functional behavior. These systems must define, in addition to their functional properties, the control of several peripheral components, of their constraints, communication interfaces and temporal and non-functional requirements. Understanding the representation and treatment of several properties of real-time and embedded systems has direct influence in their development, reliability and safety. Therefore, it is pertinent to analyze the properties that represent this domain and to provide strategies for a complete definition of model elements'. This paper aims to provide guidelines for comprehension, application and possible adoption of the UML MARTE (Modelling and Analysis of Real Time and Embedded Systems) profile in specification, modeling and design of real-time and embedded properties of a system. The proposed design strategy is applied to a case study, in the domain of intelligent automation systems, in order to direct the adoption of the constructors of MARTE profile in other development contexts and to describe the semantics and syntax of these builders to strengthen their comprehensibility.

Describing the architecture of real-time systems by means of semi-formal languages has been often considered in the literature. However, the most common approach is to propose multiple modeling languages in an orthogonal manner, i.e., the models are used in separate phases, in a totally independent way. This situation is not always possible, and the assumption in this paper is to propose a technique in which diagrams from two modeling languages are integrated. In this paper, UML and SysML are used together. Thus, the proposed technique is capable of modeling both software and system architectural elements, by satisfying the following modeling criteria: support to model components and connectors, both graphical and textual syntax, modeling non-functional requirements, design of structural view of software using UML classes, represent hardware elements in the architecture, and to describe traceability between requirements. A case study on a real-time automotive embedded system is presented to illustrate the technique.

Development of cyber-physical systems include analysis and comprehension of multiple disciplines including mechanical engineering, electronic engineering, systems engineering and computer science. In this research, two consolidated approaches of Model-Based Engineering are used in a combined way for proposing a methodology for requirements analysis, modeling and formal specification of cyber-physical systems. At first, it presents the analysis and classification of the overall system requirements, at high level of abstraction, in order to relate them with the semantics of the MARTE profile. Subsequently, graphical models are presented in the proposed methodology in accordance with formalization of restrictions, annotations and stereotypes through MARTE/VSL. First results of the application of the proposed methodology are presented by means of a case study in the Industrial Packing System domain.

Activities of specification, analysis and design of real-time systems (RTS) are highly dependent on an effective understanding of the application domain and on the thorough representation of their basic requirements. Model-based approaches using modeling languages such as UML are often applied to contribute to handle complexity of RTS development. However, UML alone does not completely represent important features associated with these systems, such as relationship with hardware elements and an effective representation of timing constraints. This article explores the combined use of UML and its profiles SysML and MARTE for modeling hardware and software requirements of RTS, with application to a case of controlling urban road traffic. The SysML profile alone does not present the representation of temporal, behavioral and performance requirements. The MARTE profile provides key resources to specify non-functional requirements for RTS, in addition to a clear description of the various relevant aspects of requirements definition of RTS, as for instance, temporal aspects and constraints. The main objective is to present the combined application of SysML with MARTE stereotypes, which enables the specification of different features of individual software requirements. Thus, in addition to the factors mentioned above, we can say that the proposed approach has an important role to specify RTS at different levels of detail and levels of abstraction.

Modeling and tracing requirements are difficult, error-prone activities which have great impact on the overall software development process. Most techniques for modeling requirements present a number of problems and limitations, including modeling requirements at a single level of abstraction, and being specific to model functional requirements. In addition, non-functional requirements are frequently overlooked. Without the proper modeling of requirements, the activity of tracing requirements is impaired. This article aims to perform a study on modeling requirements of Real-Time Systems through an extension of the SysML Requirements Diagram focusing on the traceability of non-functional and functional requirements. The SysML metamodel is extended with new stereotypes and relationships, and the proposed metamodel is applied to a set of requirements for the specification of a Road Traffic Control System. The proposed approach has demonstrated to be effective for representing software requirements of real-time systems at multiple levels of abstraction and classification. The proposed metamodel represents concisely the traceability of requirements at a high level of abstraction.

Most techniques for modeling requirements present many problems and limitations, including modeling requirements at a single level of abstraction, and are specific to model functional requirements. The objective of this article is to perform a study on modeling requirements of Real-Time Systems through an extension of the SysML Requirements Diagram focusing on the traceability of non-functional and functional requirements. The proposed approach has demonstrated to be effective for representing software requirements of real-time systems at multiple levels of abstraction and classification. The proposed metamodel represents concisely the traceability of requirements in a high abstraction level.