Formalization and Verification of Hierarchical Use of Interaction Overview Diagrams Using Timing Diagrams

Thanks to its graphical notation and simplicity, Unified Modeling Language (UML) is a de facto standard and a widespread language used in both industry and academia, despite the fact that its semantics is still informal. The Interaction Overview Diagram (IOD) is introduced in UML2; it allows the specification of the behavior in the hierarchical way. This paper is a contribution towards a formal dynamic semantics of UML2. We start by formalizing the Hierarchical use of IOD. Afterward, we complete the mapping of IOD, Sequence Diagrams and Timing Diagrams into Hierarchical Colored Petri Nets (HCPNs) using the Timed colored Petri Nets (timed CP-net). Our approach helps designers to get benefits from abstraction as well as refinement at more than two levels of hierarchy which reduces verification complexity.Comment: 8 pages, 6 figure

Model interoperability via model driven development

It is widely recognised that software development is a complex process. Among the factors that contribute to its inherent complexity is the gap between the design and the formal analysis domains. Software design is often considered a human oriented task while the analysis phase draws on formal representation and mathematical foundations. An example of this dichotomy is the use of UML for the software design phase and Petri Nets for the analysis; a separation of concerns that leads to the creation of heterogeneous models. Although UML is widely accepted as a language that can be used to model the structural and behavioural aspects of a system, its lack of mathematical foundations is seen as a serious impediment to rigorous analysis. Petri Nets on the other hand have a strong mathematical basis that is well suited for formal analysis; they lack however the appeal and the easeof-use of UML. A pressing concern for software developers is how to bridge the gap between these domains and allow for model interoperability and the integration of different toolsets across them, and thus reduce the complexity of the software development process. The aim of this paper is to present a Model Driven Development (MDD) model transformation which supports a seamless transition between UML and Petri Nets. This is achieved by model interoperability between UML Sequenc

Model-based development of energy-efficient automation systems

Der Energieverbrauch ist ein immer wichtigeres Entscheidungskriterium, das bei der Suche nach guten architektonischen und gestalterischen Alternativen technischer Systeme einbezogen werden muss. Diese Monographie stellt eine Methodik für das modellbasierte Engineering energieeffizienter Automatisierungssysteme vor. In dieser Monografie wird ein eingebettetes System als eine Kombination der Prozessorhardware und des Softwareteils betrachtet. Im entwickelten Verfahren wird der erste Teil durch ein Betriebsmodell (operational model) beschrieben, das alle möglichen Zustände und Übergänge des betrachteten Systems darstellt. Der letzte Teil wird durch ein Anwendungsmodell (application model) repräsentiert, das den Arbeitsablauf eines konkreten für dieses System erstellten Programms widerspiegelt. Gemeinsam werden die beiden Modelle in ein stochastisches Petri-Netz umgewandelt, um eine Analyse des Systems zu ermöglichen. Die entwickelten Transformationsregeln werden vorgestellt und mathematisch beschrieben. Es ist dann möglich, die Leistungsaufnahme des Systems mittels einer Standardauswertung von Petri-Netzen vorherzusagen. Die UML (vereinheitlichte Modellierungssprache) wird in dieser Monographie für die Modellierung der Echtzeitsysteme verwendet. Die mit dem MARTE-Profil (Modellierung und Analyse der Echtzeit- und eingebetteten Systeme) erweiterten Zustandsübergangsdiagramme sind für die Modellierung und Leistungsbewertung ausgewählt. Die vorgestellte Methodik wird durch eine Implementierung der notwendigen Algorithmen und grafischen Editoren in der integrierten Entwicklungsumgebung TimeNET unterstützt. Die entwickelte Erweiterung implementiert die vorgestellte Methode zur Modellierung und Bewertung des Energieverbrauchs basierend auf den erweiterten UML-Modellen, die nun automatisch in ein stochastisches Petri-Netz transformiert werden können. Der Energieverbrauch des Systems kann dann durch die Analyse-Module für stochastische Petri-Netze von TimeNET vorhergesagt werden. Die Vorteile der vorgeschlagenen Methode werden anhand von Anwendungsbeispielen demonstriert.Power consumption is an increasingly important decision criterion that has to be included in the search for good architectural and design alternatives of technical systems. This monograph presents a methodology for the model-based engineering of energy-aware automation systems. In this monograph, an embedded system is considered as an alliance of the processor hardware and the software part. In the developed method, the former part is described by an operational model, which depicts all possible states and transitions of the system under consideration. The latter part is represented by an application model, which reflects the workflow of a concrete program created for this system. Together, these two models are translated into one stochastic Petri net to make analyzing of the system possible. The developed transformation rules are presented and described mathematically. It is then possible to predict the system’s power consumption by a standard evaluation of Petri nets. The Unified Modeling Language (UML) is used in this monograph for modeling of real-time systems. State machine diagrams extended with the MARTE profile (Modeling and Analysis of Real-Time and Embedded Systems) are chosen for modeling and performance evaluation. The presented methodology is supported by an implementation of the necessary algorithms and graphical editors in the software tool TimeNET. The developed extension implements the presented method for power consumption modeling and evaluation based on the extended UML models, which now can be automatically transformed into a stochastic Petri net. The system’s power consumption can be then predicted by the standard Petri net analysis modules of TimeNET. The methodology is validated and its advantages are demonstrated using application examples

Платформи з LCNC і їх відмінності від SOA на прикладі сенсорних медичних систем

Дану роботу присвячено порівнянню різних методів розробки систем. Це порівняння класичного традиційного програмування за концепцією SOA та відносно нової розробки на low-code/no-code платформах. У даній роботі проводиться аналіз технічної та бізнес-літератури, де описується загалом або детально кожен з методів розробки, розглядається тлумачення цих концепцій розробки під різними поглядами науковців, звичайних розробників та бізнес-аналітиків. Розглядається історичне становлення та причини, що призвели до виникнення архітектурної концепції SOA, поява та опис технологій, що зробили втілення концепції реальним. Також описуються причини виникнення LC/NC платформ як способу вирішення проблем сучасного бізнесу: нестачі часу та заощадження коштів. Теоретичне порівняння різних методів розробки підкріплюється практичним порівнянням на основі створення реального застосунку. Додаток, що розробляється та порівнюється є MVP медичної сенсорної системи, що має практичну користь у використанні її пацієнтами та лікарями за спостереженням зміни певних значень показників. Застосовуються такі середовища розробки як Android Studio, Visual Studio та OutSystems Service Studio. На основі практичного порівняння в роботі підкріплюються або спростовуються тезиси переваг та недоліків кожного з методів розробки. Виокремлюються окремі рекомендації застосувань LC/NC платформ та традиційної концепції SOA під окремі задачі. Загальний обсяг пояснювальної записки: 186 сторінок, включаючи 139 рисунків, 10 таблиць та 72 посилання.This work is devoted to the comparison of different methods of systems development. This is a comparison of classic traditional concept SOA programming and relatively new development on low-code / no-code platforms. This work analyzes the technical and business literature, which describes in general or in detail each of the development methods, and the interpretation of these development concepts under the different views of scientists, ordinary developers, and business analysts. The historical formation and the reasons that led to the emergence of the architectural concept of SOA, the emergence and description of technologies that made the implementation of the concept real. It also describes the reasons for the emergence of LC / NC platforms as a way to solve modern business problems: lack of time and savings. Theoretical comparison of different development methods is supported by practical comparisons based on the creation of a real application. The application developed and compared is the MVP of the medical sensor system, which has practical benefits in its use by patients and physicians to monitor changes in certain values. Development environments such as Android Studio, Visual Studio, and OutSystems Service Studio are used. On the basis of practical comparison in the work, the theses of advantages and disadvantages of each of the development methods are supported or refuted. Some recommendations for the use of LC / NC platforms and the traditional concept of SOA for individual tasks are highlighted. Total explanatory note volume: 186 pages, including 139 images, 10 tables and 72 references

The Impact of Petri Nets on System-of-Systems Engineering

The successful engineering of a large-scale system-of-systems project towards deterministic behaviour depends on integrating autonomous components using international communications standards in accordance with dynamic requirements. To-date, their engineering has been unsuccessful: no combination of top-down and bottom-up engineering perspectives is adopted, and information exchange protocol and interfaces between components are not being precisely specified. Various approaches such as modelling, and architecture frameworks make positive contributions to system-of-systems specification but their successful implementation is still a problem. One of the most popular modelling notations available for specifying systems, UML, is intuitive and graphical but also ambiguous and imprecise. Supplying a range of diagrams to represent a system under development, UML lacks simulation and exhaustive verification capability. This shortfall in UML has received little attention in the context of system-of-systems and there are two major research issues: 1. Where the dynamic, behavioural diagrams of UML can and cannot be used to model and analyse system-of-systems 2. Determining how Petri nets can be used to improve the specification and analysis of the dynamic model of a system-of-systems specified using UML This thesis presents the strengths and weaknesses of Petri nets in relation to the specification of system-of-systems and shows how Petri net models can be used instead of conventional UML Activity Diagrams. The model of the system-of-systems can then be analysed and verified using Petri net theory. The Petri net formalism of behaviour is demonstrated using two case studies from the military domain. The first case study uses Petri nets to specify and analyse a close air support mission. This case study concludes by indicating the strengths, weaknesses, and shortfalls of the proposed formalism in system-of-systems specification. The second case study considers specification of a military exchange network parameters problem and the results are compared with the strengths and weaknesses identified in the first case study. Finally, the results of the research are formulated in the form of a Petri net enhancement to UML (mapping existing activity diagram elements to Petri net elements) to meet the needs of system-of-systems specification, verification and validation

Analysis and Optimization of Mobile Business Processes

Mobility of workers and business processes rapidly gains the attention of businesses and business analysts. A wide variety of definitions exists for mobile business processes. This work considers a type of business processes concerned with the maintenance of distributed technical equipment as, e.g., telecommunication networks, utility networks, or professional office gear. Executing the processes in question, workers travel to the location where the equipment is situated and perform tasks there. Depending on the type of activities to be performed, the workers need certain qualifications to fulfill their duty. Especially in network maintenance processes, activities are often not isolated but depend on the parallel or subsequent execution of other activities at other locations. Like every other economic activity, the out- lined mobile processes are under permanent pressure to be executed more efficiently. Since business process reengineering (BPR) projects are the common way to achieve process improvements, business analysts need methods to model and evaluate mobile business processes. Mobile processes challenge BPR projects in two ways: (i) the process at- tributes introduced by mobility (traveling, remote synchronization, etc.) complicate process modeling, and (ii) these attributes introduce process dynamics that prevent the straightforward prediction of BPR effects. This work solves these problems by developing a modeling method for mobile processes. The method allows for simulating mobile processes considering the mobility attributes while hiding the complexity of these attributes from the business analysts modeling the processes. Simulating business processes requires to assign activites to workers, which is called scheduling. The spatial distribution of activities relates scheduling to routing problems known from the logistics domain. To provide the simula- tor with scheduling capabilities the according Mobile Workforce Scheduling Problem with Multitask-Processes (MWSP-MP) is introduced and analyzed in-depth. A set of neighborhood operators was developed to allow for the application of heuristics and meta-heuristics to the problem. Furthermore, methods for generating start solutions of the MWSP-MP are introduced. The methods introduced throughout this work were validated with real-world data from a German utility. The contributions of this work are a reference model of mobile work, a business domain independent modeling method for mobile business processes, a simulation environment for such processes, and the introduction and analysis of the Mobile Workforce Scheduling Problem with Multitask-Processes

Modelling and verification of ambient systems using petri nets

PhD ThesisThe expeditious development of technology in the past decades re- sulted in the introduction of concurrent systems that incorporate both ubiquitous and pervasive computing, the ambient systems. These sys- tems are named after their ability to be completely embedded in the environment in which they operate and interact with the users, in a silent and non distracting way, facilitating the completion of their tasks. Hence, there is a growing need to introduce and develop formal tech- niques for computational models capable of faithfully modelling the behaviour of these systems. One way of capturing the intricate be- haviours of the ambient systems is to use Petri nets, which are a modelling language that is used for the representation and analysis of concurrent systems. Within the domain of rigorous system design, veri cation of systems e ectively checks and guarantees the correctness of the examined mod- els with respect to the speci cation. This work investigates the modelling and the analysis of ambient sys- tems using Petri nets. To examine the modelling of these systems, their taxonomy into Ambient Guidance Systems and Ambient Infor- mation Systems is carried out and a case study is used for the mod- elling of each category. To model ambient systems, the step-modelling approach and a vari- ant class of Coloured Petri Nets, the Ambient Petri Nets (APNs), are introduced. Step modelling approach focuses on the interaction be- tween the system and the user and Ambient Petri Nets is a class of nets with colour-sensitive inhibitor arcs that is used especially for the structural and behavioural representation of ambient systems. For the modelling of general ambient systems, the compositionality of the Ambient Petri Nets is used. To verify the correctness of the produced Ambient Petri Nets models, the introduction of the Transformed Ambient Petri Nets class that has no colour-sensitive inhibitor arcs is required since Charlie and generally most of the existing veri cation tools do not support the analysis of inhibitor nets. To address this problem, a construction is de ned to translate the Ambient Petri Nets into Transformed Ambient Petri Nets. Afterwards, the Step Transition Systems are used to prove the behavioural equivalence of the nets that are associated through the construction. Subsequently, the Transformed Ambient Petri Nets models of the cho- sen case studies are veri ed against model checking and qualitative properties. For the rst category, Computation Tree Logic (CTL) is used to check the models against important properties of the ambient systems that are related to their features and their general function- ing. Finally, qualitative properties consider fundamental structural and behavioural properties of Petri nets that provide useful outcome about the systems under consideration