Composition of software artifacts modelled using Colored Petri nets

Component based software engineering has been claimed as a suitable approach to improve the flexibility and reuse in software development. In this context, the Compor infrastructure provides mechanisms to promote the dynamic composition of software systems, addressing applications with support for unanticipated requirement changes. In this paper, the formal modelling and verification of the COMPOR component model is presented. Hierarchical Colored Petri Nets are used for modelling and simulation, purposing to show the correct behavior for some scenarios. Model checking is used to prove that the scenarios analyzed with simulation are correct for all possible behaviors of the model.

The paper presents the results of research on the use of hierarchical models with colored Petri nets in the evaluation of automated systems for the preparation and analysis of metallographic specimens. Modeling with hierarchical colored Petri nets was used to evaluate the performance of a preparation and analysis robotic system for metallographic samples. The automated system is composed of three subsystems: the subsystem for the preparation of metallographic samples, the subsystem for the attack with reagent of metallographic samples, the subsystem for the analysis of metallographic samples. Two models were made: a model with colored Petri nets with simple colors and a model with timed colored Petri nets with complex colors. Each model was developed on two hierarchical levels. Level 1 contains the model of the entire flexible system for the preparation and analysis of metallographic samples. Level 2 consists of three sub-models: the sub-model of the system for the preparation of metallographic samples, the sub-model of the system for the reagent attack of metallographic samples, the sub-model of the system for the analysis of metallographic samples. Models with timed colored Petri nets allow the evaluation of system performance in terms of the number of samples analyzed in a time interval. The performance of the modeled system was evaluated by simulation, considering a time interval of eight hours.

A railway interlocking system (RIS) plays a vital role in the safe transportation of a railway system. It is responsible for the safe routes of trains making sure that each train movement follows the other in a proper and safe sequence. Detailed verifications and evaluations are mandatory before deploying an RIS, since it is a safety critical system (SCS). But the increasing complexity of the RIS tends to limit the capability of the classic approval methods. As a result, the formalization of RIS becomes important to both the development of computer interlocking software and the third-party testing of the RIS facilities. Petri nets are a powerful formal tool that have been applied to many railway applications. Considering the large scale and the space complexity of interlocking systems, this paper introduces a feasible method for modeling the RIS by hierarchical colored Petri net (HCPN), which aim at providing a formal verification and logic evaluation of the French RIS. The paper describes how the signaling control logical and the railway road layout are specified and constructed into the HCPN. First, the architecture of RIS and the hierarchical structure of the model framework are introduced. Then, several basic RIS components are established as Petri nets to illustrate how to map RIS components into HCPN. As a case study, a section of a typical French station is modeled. It includes interlocking routes and signaling control principles. This paper takes place in the framework of the ANR project ‘PERFECT’. As this method has already received recognition from French railway experts, the future research contains consistency checking with some other parts of the specification, such as operation rules, which allows the authors to find out the crux of some existing problems and to discover some potential safety hazards.

An optimized streamline online score system is the key to score efficiently and effectively. In this paper, an approach of modeling and optimizing the online score process was proposed using the Hierarchical Colored Petri Nets (HCP-nets). Founded on the HCP-net based online score process model, CPN Tools, a Colored Petri Nets simulation tool, was adopted to evaluate the outer and inner performances of the system, such as scan, score, and resource utilization. Model checking is performed in CPN Tools. After state space analysis, the concurrency, conflict and causal dependency in the online score process are illustrated. According to the results, the service efficiency and service quality of online score system are improved by applying the methods of process redesign and optimization like combining tasks and integrating resources.

Aiming at the difficulties of modeling and verification of interlocking system and the easy explosion problem of interlocking system state space, a modeling method of interlocking system is proposed based on UML and Hierarchical Colored Petri Nets (HCPN). Firstly, UML is used to realize the semi-formal modeling of the interlocking system, which can reduce the difficulties of modeling interlocking system. Secondly, the UML-CPN transformational rules are used to establish the HCPN layered model of the interlocking system to alleviate the explosion problem of the system state space. Finally, the formal verification of the HCPN model is realized by using CPN Tools. The interlocking modeling method based on UML and HCPN can provide a new idea for the formal modeling and verification of computer interlocking system.

Systems biology aims to facilitate the understanding of complex interactions between components in biological systems. Petri nets (PN), and in particular Coloured Petri Nets (CPN) have been demonstrated to be a suitable formalism for modelling biological systems and building computational models over multiple spatial and temporal scales. To explore the complex and high-dimensional solution space over the behaviours generated by such models, we propose a clustering methodology which combines principal component analysis (PCA), distance similarity and density factors through the application of DBScan. To facilitate the interpretation of clustering results and enable further analysis using model checking we apply a pattern mining approach aimed at generating high-level classificatory descriptions of the clusters' behaviour in temporal logic. We illustrate the power of our approach through the analysis of two case studies: multiple knockdown of the Mitogen-activated protein-kinase (MAPK) pathway, and selective knockout of Planar Cell Polarity (PCP) signalling in Drosophila wing.

The integration of complex software systems such as clinical decision aid platforms and electronic health records (EHR) has substantially improved human healthcare support by enhancing diagnostic accuracy and optimizing medical workflows. Developing these systems requires meticulous processes including requirement specification, design, implementation, testing, and deployment. While numerous approaches exist for system development, formal verification through modeling has become crucial for ensuring system reliability and security. In this research, an approach based on Hierarchical Colored Petri-Nets (HCP-Nets) for process modeling and formal verification to develop an EHR system is proposed that is accurate, complete, and consistent. The World Health Organization (WHO) emphasizes integrating modern computing techniques such as data mining and machine learning into health systems in the context of viral disease outbreaks and the need for robust public health surveillance. There is a critical need for process mining and formal verification-based systems to improve data sharing and system integration in regions like Pakistan, where healthcare infrastructure and interoperability are limited. This research addresses key gaps in EHR systems including platform effectiveness, data storage consistency, data accuracy, completeness, and security against unauthorized access. The findings suggest that formal verification using HCP-Nets with model checking and process mining can greatly enhance the reliability and security of EHR systems with an accuracy of 80 5%, providing a strong foundation to advance health informatics and supporting better health outcomes in complex and diverse environments.

The approach aims at solving the above problems by including the analysis and verification of two different levels of software development process–design level and implementation level-and bridging the gap between software architecture analysis and verification and the software product. In the architecture design level, to make sure the design correctness and attack the large scale of complex systems, the compositional verification is used by dividing and verifying each component individually and synthesizing them based on the driving theory. Then for those properties that cannot be verified on the design level, the design model is translated to implementation and runtime verification technique is adapted to the program. This approach can highly reduce the work on the design verification and avoid the state-explosion problem using model checking. Moreover, this approach can ensure both design and implementation correctness, and can further provide a high confident final software product. This approach is based on Software Architecture Model (SAM) that was proposed by Florida International University in 1999. SAM is a formal specification and built on the pair of component-connector with two formalisms – Petri nets and temporal logic. The ACV approach places strong demands on an organization to articulate those quality attributes of primary importance. It also requires a selection of benchmark combination points with which to verify integrated properties. The purpose of the ACV is not to commend particular architectures, but to provide a method for verification and analysis of large scale software systems in architecture level. The future research works fall in two directions. In the compositional verification of SAM model, it is possible that there is circular waiting of certain data among different component and connectors. This problem was not discussed in the current work. The translation of SAM to implementation is based on the restricted Petri nets due to the undecidable issue of high level Petri nets. In the runtime analysis of implementation, extraction of the execution trace of the program is still needed to get a white box view, and further analysis of execution can provide more information of the product correctness.

The description of the design and automation of a hard nickel electroplating pilot plant using rectangular pulse current is presented. For the automation of this process the Petri nets (PN) are described and used, starting from their more basic form and justifying why to use higher levels of abstraction or extensions of the same ones. These levels include the IPN (Interpreted PN), HPN (Hierarchical PN) and, finally, as a complement to this article the use of the HCPN (Hierarchical Colored PN). The results are reflected in the reduction of the pattern complexity due to the properties of modularization of the nets of higher level.

Workflows are a technology to structure work in functional, non-overlapping steps. They define
\nnot only the order of execution of the steps, and describe whether steps are executed in
\nparallel, they also specify who or what tool has to fulfill which step. Workflows offer the possibility
\nto automate work, to increase the understandability of processes, and they ease the
\ncontrol of process execution. The tools to manage workflows, so called workflow management
\nsystems (WfMSs), are traditionally rigid as they separate workflow definition done at build time
\nfrom workflow execution done at run time. This makes them ill-suited for managing flexible and
\nunstructured workflows. In this thesis, we focus on the support of flexible processes in eHealth,
\nwhich are affected by more foreseen than unforeseen events. To bridge the gap between rigid
\nWfMSs and flexible workflows, we developed a concept for dynamic and context-aware workflow
\nmanagement called Flexwoman. Although our focus lies on flexible eHealth processes,
\nFlexwoman is a generic approach that can be applied to several different application domains.
\nFlexwoman supports the usage of context information to adapt processes automatically at run
\ntime to foreseen events. Processes can also be manually adapted to handle unforeseen events.
\nTo achieve this flexibility, context information from different sensors is unified and thus can be
\nanalyzed in the same way. The analysis and adaptation of workflows is executed with a rule engine.
\nA rule engine can store, reason about and apply knowledge automatically and efficiently.
\nRules and application logic are separated, thus, rules can be changed during run time without
\naffecting application logic or process description. Workflows are internally described by Hierarchical
\nColored Petri nets (HCPNs) and executed by a HCPN execution engine. HCPNs allow for
\na deterministic execution of workflows and can represent workflows on different levels of detail.
\nIn summary, in Flexwoman, significant context changes (events) trigger automated adaptations
\nthat replace parts of the workflow by sub workflows, which can in turn be adapted. The adaptations
\nand the rules for context-aware adaptation are saved in the organizational memory for
\nlater reuse. Flexwoman’s event based behavior facilitates proactive adaptations instead of only
\nallowing for adaptations while entering or leaving a task. Replacements are not bound to special
\nplaces defined at build time but each part of the workflow, which has not been executed yet, can
\nbe replaced at run time. We implemented and evaluated the concept. The evaluations show
\ni) that all required functionality is available, ii) that the system scales with a growing number of
\nrules, and iii) that the system correctly handles failure situations.

Offshore oil drilling is a complex process that requires careful coordination of hardware and control systems. Fault monitoring systems play an important role in such systems for safe and profitable operations. Thus, predictive maintenance and monitoring operating conditions of drilling systems are critical to the overall production cycle. In this paper, we are addressing the topic of condition monitoring of a critical part in the process of oil drilling, the Internal Blowout Preventer (IBOP) system in the top drive assembly in offshore oil drilling. In our work, we aim to design an intelligent system for monitoring the health of IBOP system using discrete event systems (DES) based control method in combination with multivariate time series classification deep learning method. The proposed system comprises two stages: 1) produce IBOP system logical behaviour analysis using Hierarchical Colored Petri Nets (HCPN) approach; 2) develop an activity detection or a classifier module using reservoir computing framework for classification of multivariate time series for activity monitoring and fault detection for the top drive assembly.
 The combination of these methods would enable automation of monitoring and early detection of incidents during drilling operations. We present the preliminary results of a model in Petri Nets used to simulate a monitoring system for IBOP valve in top drive assembly and activity classification of activities relevant to IBOP condition monitoring. The effects of failure rate and repair time of each component on system performance are to be researched at a later stage.

The paper is a partial synthesis of the work that a team within the Faculty of Managerial and Technological Engineering has in the field of modeling and simulation of systems with Petri nets. The paper deals with three issues. The first part is Modeling and simulation of manufacturing systems with timed Petri nets. The first part presents the way in which the performances of some manufacturing systems are evaluated using timed Petri nets. The first example is a manufacturing system specific to the textile industry. The system has three production lines. In this case, the modeling with timed Petri nets allows the analysis of the operation of the flow lines and highlights the bottleneck. Another modeled manufacturing system is specific to a series production, more precisely it refers to the manufacture of gas cookers within a company from Oradea. The model with Petri nets also describes the supply sequences of the stocks of parts and subassemblies. The next modeled system is an automated manufacturing system for the packaging of detergents. The complexity of the Detergent Packing System and the high level of automation, require the use of efficient modeling and simulation methods to verify the validity of the solutions adopted. In this chapter is present the model of a robotic welding cell. The second part of the paper, the transition from timed Petri nets to hierarchical colored Petri nets, shows how Petri nets were developed for a robotic cell for metallographic analysis. The third part is dedicated to modeling with colored Petri nets timed with complex colors of the flexible manufacturing cell A007 within the Department of Industrial Engineering.

With the aim of solving the problems of the Petri nets to the place/transition nets automatic conversion and realization of Petri nets parallel control and running, the algorithm is proposed to transform Color Petri net systems transform into P/T nets. The algebraic model of colored Petri nets and P/T nets, and its intrinsic mechanism is analyzed, the process and theory verification of the colored Petri nets into P/T nets are given. The colored Petri nets into P/T network algorithm is proposed, through the network model of formal, colored Petri nets correlation matrix pretreatment. Experimental results show that it is an effective method to solve Color Petri Net systems transform into P/T nets, lay the foundation for various senior Petri nets system transformation into P/T nets and achieve the parallelism and simulation of running.

The context of our work is the complex systems simulation. Complex systems modelling and simulation require to take into account the interactions between the different components. For instance, an airport ground traffic simulation requires to model the planes with the pilots, the control tower, the

The verification of access controls is essential for providing secure systems. Model checking is an automated technique used for verifying finite state machines. The properties to be verified are usually expressed as formula in temporal logic. In this paper we present an approach to verify access control security properties of a security annotated business process model. To this end we utilise a security enhanced BPMN notation to define access control properties. To enhance the usability the complex and technical details are hidden from the process modeller by using an automatic translation of the process model into a process meta language (Promela) based on Coloured Petri net (CPN) semantics. The model checker SPIN is used for the process model verification and a trace file is written to provide visual feedback to the modeller on the abstraction level of the verified process model. As a proof of concept the described translation methodology is implemented as a plug-in for the free web-based BPMN modelling tool Oryx.