Colored Petri Net Model Research Articles

Transformation of the BPMN Design Model into a Colored Petri Net Using the Partitioning Approach

Formal verification is a process to ensure that the business process model and notation (BPMN) design model is free of deadlock, livelock, and other undesirable properties that can cause a system crash. Formal verification is a complicated procedure involving model abstraction and model checking tools used for property checking. There are several existing transformation techniques that yield an abstract model, but the data perspective is not considered. These techniques are also inappropriate for the large-scale BPMN design model. An automated transformation can reduce the flaws, time consumption, and complexity of the large-scale BPMN design model. This paper proposes a transformation technique and provides a framework for transforming the BPMN design models into colored Petri nets (CPNs). Our techniques cover both the control-flow and data-flow perspectives. The partitioning technique of the BPMN design model is applied to reduce the complexity and leads to a CPN model that can support the hierarchical and compositional verification techniques that are suitable for the large-scale BPMN design models. The proposed transformation has been implemented as a transformation framework and is able to consistently transform the BPMN design models into CPN models.

Modeling and Analysis of the 1-Wire Communication Protocol Using Timed Colored Petri Nets

The widespread use of sensor networks has enabled the deployment of a wide variety of services. In order to reduce maintenance costs without jeopardizing the reliability of the services, developers and researchers are exploring ways to reduce the complexity of the protocols and their underlying hardware infrastructure. However, the verification and evaluation of novel solutions must also be taken as a key design parameter in the development of reliable and cost-effective solutions. In this paper, we develop a timed colored Petri net (TCPN) model of the 1-wire protocol, which is one of the most popular and simplest protocols currently used in the implementation of sensor platforms. The use of TCPNs is justified by the fact that they provide us with the means to evaluate the qualitative and quantitative properties of the protocol. Our results include the analysis of the absence of deadlocks as well as the quantitative evaluation of the protocol. Our numerical results are also confirmed by using an event-driven simulator.

Validation of a Distributed Energy Management Approach for Smart Grid Based on a Generic Colored Petri Nets Model

Validation of a Distributed Energy Management Approach for Smart Grid Based on a Generic Colored Petri Nets Model

Modeling and Analysis of Protein Synthesis and DNA Mutation Using Colored Petri Nets

In molecular biology, protein synthesis is an essential biological process of generating specific proteins in living systems. Many mathematical models are designed to characterize the process of the flow of genetic information from deoxyribonucleic acid (DNA) to protein; however, most of them cannot provide detailed and observed steps to describe and analyze this fundamental biological process. Colored Petri Net (CPN), as a mathematical method widely applied in the process analysis of discrete event dynamic systems, has increasingly become an innovative and efficient theoretical approach for exploring the biological processes. Aiming at describing the entire process of protein synthesis, a CPN-based model has been designed that successfully and intuitively represents the flow of genetic information involving transcription and translation. DNA mutations are permanent alterations in the nucleotide sequence of the DNA strand, while different types of mutations have various effects on the synthesized proteins. Based on the proposed protein synthesis model, we put forward a new CPN model to identify the type of mutation, which is beneficial for analyzing whether the mutation has impacts on the structure or function of the produced protein. The mutation position and bases mutated rate are obtained by contrasting the nucleobases on DNA sequences, while the mutation type is determined via the alignment of the amino acids in the polypeptide chain. The model’s effectiveness and accuracy are illustrated by biological mutation examples, indicating this method offers great superiority in modeling and analyzing the complex biological processes.

Recognizing and Stopping Rumors Patterns in Social Networks

Objectives: In this study, a proposed Colored Petri Net Model (CPNM) is used for recognizing and stopping rumors in Social Networks (SN). Methods/Analysis: Detecting and blocking rumors represent an open security issue in social networks. In response to this issue, the proposed CPNM is experimentally simulated on dataset consists of 863-newsworthy tweets collected from the trending topic #CharlieHebdo in Twitter. The performance of CPNM is analyzed and evaluated using Precision, Recall, and Accuracy metrics. In addition, the CPNM is verified against the Reachability as a major behavior property in Petri Nets. Findings: The practical results disclosed a superiority of the proposed CPNM in detecting accurately rumors patterns compared with other approaches in the literature. In addition, verifying the Reachability using Reachability Graph proved that detecting and blocking rumors tweets are reachable states according to the firing life-cycle of tokens. Novelty/Improvement: Detecting rumors in social networks in more accuracy and low False Positive Rate (FPR) as well as blocking its propagation over the Social Network.

A colored Petri net model for DisCSP algorithms

SummaryThe aim of this paper is to present a colored Petri net that models a system applying a DisCSP method. Our study considered 3 representative DisCSP algorithms: synchronous backtracking, asynchronous backtracking, and weak‐commitment search. To obtain the model, it was necessary to transpose the operation of a DisCSP‐based system into a discrete event system. The constructed colored Petri net is presented, with details on the information stored in places, procedures associated with transitions, and communication between agents. Through the performed trials (with the n‐queens problem), it was proved that the model is correct, easy to use, and adaptable to different operation conditions. The conducted simulations revealed new results about the way the 3 analyzed algorithms compare one with the other. It was showed that the performance of weak‐commitment search is degrading in cases close to real conditions, namely, when agents use un‐updated information about the state of system. We could also study 3 strategies for improving the performance of DisCSP algorithms, making them more practicable. The proposed model is available for open use, it is independent of the software that carries out a DisCSP method, and it can be enhanced for other DisCSP algorithms and diverse communication schemes.

Delayed maintenance modelling considering speed restriction for a railway section

The deterioration of track geometry depends on several factors of which the speed of the train is one. Imposing a speed restriction can slow down the track deterioration and allows a longer survival time before a serious condition is achieved. Preventive maintenance delays can be authorized during the survival time. However, speed restrictions also reduce the system throughput. On the other hand, a longer interval between preventive maintenance activities has a lower maintenance action cost and it also enables grouping the maintenance activities to save set-up costs as well as system downtime. If the repair delay is too long, it may cause unacceptable conditions on the track and lead to higher maintenance costs and accidents. Therefore, it is interesting to assess the effect of a speed restriction on the delayed maintenance strategies for a railway track section. We want to solve a maintenance optimization problem to find the optimal tuning of the maintenance delay time and imposition of a speed restriction. To this aim, a delayed maintenance model is developed, in which track deterioration depends on the train speed and the number of passing trains. The model is used to determine an optimal speed restriction strategy and a preventive repair delay for the optimization of the system benefit and unavailability. Coloured Petri Nets are adopted to model the maintenance and operation of the railway track section. The Coloured Petri Net model describes the gradual track deterioration as a stochastic process. Different speed restriction policies and maintenance delay strategies are modelled and activated by the observed component states. Monte Carlo simulations are carried out to estimate the maintenance cost, the system benefit and the system downtime under different policies. Numerical results show the maintenance decision variable trade-off.

A hierarchical coloured Petri net model of fleet maintenance with cannibalisation

Cannibalisation refers to a maintenance action where an unserviceable part in an inoperative platform is replaced by a serviceable part of the same type from another platform. It helps a fleet meet operational requirements when spares are in short supply but leads to more maintenance tasks to be carried out. In practice, cannibalisation may be performed in an unrestricted manner, or through the use of cannibalisation birds. A cannibalisation bird is a platform which is selected as the primary source of cannibalisation, while any inoperative platform can be a cannibalisation source under the unrestricted policy. In order to aid fleet managers in making cannibalisation-related decisions, this paper presents a hierarchical coloured Petri net (HCPN) model of a fleet operation and maintenance process which considers mission-oriented operation, multiple level maintenance, multiple cannibalisation policies (no cannibalisation, unrestricted cannibalisation and cannibalisation bird), maintenance scheduling and spare inventory management. The model is applied to an example fleet to compare the effects of different cannibalisation policies on fleet performance using a number of performance measures related to reliability and maintenance and to optimise the number of cannibalisation birds used and the length of time that a platform is taken as a cannibalisation bird for the fleet.

Diagnosis of Technological Systems Based On the Structural Decomposition of Their Coloured Petri Net Model

Abstract Diagnosing faults during the operation of a system is an essential task when investigating technological systems. In this paper, a new online fault identification method is proposed which is based on the occurrence graph of the coloured Petri net model of the system. The model is able to simulate the normal and faulty operations of the system given in the form of event lists, so called traces. The diagnosis is based on the search for deviations between the traces of the normal and the actual operations. In the case of complex technological systems, the occurrence graph can contain hundreds of nodes; therefore, the computational effort and searching-time increase significantly. Our proposed structural decomposition method can manage these demands so it has a crucial impact on the practical application of diagnostic processes. The main idea of our method is that the complex systems can be decomposed into technological units. Therefore, the diagnosis can be done by components separately and the diagnostic result of a unit can be used for the diagnosis of the other units connected to it. Because of the structural decomposition, the diagnosis has to be performed on much smaller occurrence graphs but the effect of faults in previous units is taken into account. The proposed method is illustrated by a simple case study.

Modeling cyber-physical attacks based on probabilistic colored Petri nets and mixed-strategy game theory

Cyber-physical attacks are posing great threats to the safety and security of cyber-physical systems. Modeling cyber-physical attacks reasonably and efficiently is the basis for defending cyber-physical systems effectively, which requires the development of quantitative analysis and modeling approaches for expressing threat propagation in cyber-physical systems. This paper extends the colored Petri net model by defining a probabilistic colored Petri net model that comprises basic models, rules, logical operators and transitions that describe threat propagation between nodes. Basic cyber-physical attack models based on probabilistic colored Petri nets are presented. Furthermore, a systematic modeling approach is presented for constructing a quantitative cyber-physical attack model for a cyber-physical system. The weights of the cyber-physical attack model connections are computed using a mixed-strategy attack-defense game model for each node and solving the Nash equilibrium. Additionally, a hierarchical method of division and integration is proposed to efficiently model complex, large-scale cyber-physical systems. Finally, the systematic cyber-physical attack modeling approach is applied to a case study involving a thermal power plant.

Scenario-Based Modeling of the On-Board of a Satellite-Based Train Control System With Colored Petri Nets

For the goal of model-based system design and development, this paper exploits the formalism of colored Petri nets (CPNs) to model the on-board subsystem of a satellite-based train control system on the basis of scenarios. The Unified Modeling Language sequence diagrams, which are easily understood by customers, requirement engineers, and software developers, are used to represent scenarios as specification models. A scenario is a partial description of the system behavior, describing how users, system components, and the environment interact. Thus, scenarios need to be synthesized to obtain an overall system behavior. A large number of works have investigated scenario synthesis providing approaches or algorithms. These synthesis approaches and algorithms result in either Petri net models that are mainly suitable for scenario validation or other forms of behavior models (e.g., labeled transition systems and statecharts) that may be regarded as design models. Petri nets are well known for describing distributed and concurrent systems. Furthermore, numerous techniques, e.g., simulation, testing, state-space-based techniques, structural methods, and model checking, are currently available for analyzing PN models. Therefore, design models, which integrate all scenarios into a coherent whole suitable for further detailed design, in the form of Petri nets are promising. To this end, we present a top-down approach to establish hierarchical CPNs in accordance with specified scenarios (i.e., sequence diagrams). This approach makes use of explicitly labeling component states in the sequence diagrams to correlate scenarios. In addition, the techniques of state-space analysis and model-based testing are employed to verify the correctness and consistency of the CPN model with respect to standard and system-specific properties. The verification results show that our approach is desirable.

A Novel Petri Nets-Based Modeling Method for the Interaction between the Sensor and the Geographic Environment in Emerging Sensor Networks.

The service of sensor device in Emerging Sensor Networks (ESNs) is the extension of traditional Web services. Through the sensor network, the service of sensor device can communicate directly with the entity in the geographic environment, and even impact the geographic entity directly. The interaction between the sensor device in ESNs and geographic environment is very complex, and the interaction modeling is a challenging problem. This paper proposed a novel Petri Nets-based modeling method for the interaction between the sensor device and the geographic environment. The feature of the sensor device service in ESNs is more easily affected by the geographic environment than the traditional Web service. Therefore, the response time, the fault-tolerant ability and the resource consumption become important factors in the performance of the whole sensor application system. Thus, this paper classified IoT services as Sensing services and Controlling services according to the interaction between IoT service and geographic entity, and classified GIS services as data services and processing services. Then, this paper designed and analyzed service algebra and Colored Petri Nets model to modeling the geo-feature, IoT service, GIS service and the interaction process between the sensor and the geographic enviroment. At last, the modeling process is discussed by examples.

STOCHASTIC COLOURED PETRINET BASED HEALTHCARE INFRASTRUCTURE INTERDEPENDENCY MODEL

Abstract. The Healthcare Critical Infrastructure (HCI) protects all sectors of the society from hazards such as terrorism, infectious disease outbreaks, and natural disasters. HCI plays a significant role in response and recovery across all other sectors in the event of a natural or manmade disaster. However, for its continuity of operations and service delivery HCI is dependent on other interdependent Critical Infrastructures (CI) such as Communications, Electric Supply, Emergency Services, Transportation Systems, and Water Supply System. During a mass casualty due to disasters such as floods, a major challenge that arises for the HCI is to respond to the crisis in a timely manner in an uncertain and variable environment. To address this issue the HCI should be disaster prepared, by fully understanding the complexities and interdependencies that exist in a hospital, emergency department or emergency response event. Modelling and simulation of a disaster scenario with these complexities would help in training and providing an opportunity for all the stakeholders to work together in a coordinated response to a disaster. The paper would present interdependencies related to HCI based on Stochastic Coloured Petri Nets (SCPN) modelling and simulation approach, given a flood scenario as the disaster which would disrupt the infrastructure nodes. The entire model would be integrated with Geographic information based decision support system to visualize the dynamic behaviour of the interdependency of the Healthcare and related CI network in a geographically based environment.

STOCHASTIC COLOURED PETRINET BASED HEALTHCARE INFRASTRUCTURE INTERDEPENDENCY MODEL

The Healthcare Critical Infrastructure (HCI) protects all sectors of the society from hazards such as terrorism, infectious disease outbreaks, and natural disasters. HCI plays a significant role in response and recovery across all other sectors in the event of a natural or manmade disaster. However, for its continuity of operations and service delivery HCI is dependent on other interdependent Critical Infrastructures (CI) such as Communications, Electric Supply, Emergency Services, Transportation Systems, and Water Supply System. During a mass casualty due to disasters such as floods, a major challenge that arises for the HCI is to respond to the crisis in a timely manner in an uncertain and variable environment. To address this issue the HCI should be disaster prepared, by fully understanding the complexities and interdependencies that exist in a hospital, emergency department or emergency response event. Modelling and simulation of a disaster scenario with these complexities would help in training and providing an opportunity for all the stakeholders to work together in a coordinated response to a disaster. The paper would present interdependencies related to HCI based on Stochastic Coloured Petri Nets (SCPN) modelling and simulation approach, given a flood scenario as the disaster which would disrupt the infrastructure nodes. The entire model would be integrated with Geographic information based decision support system to visualize the dynamic behaviour of the interdependency of the Healthcare and related CI network in a geographically based environment.

An integrated hazard identification method based on the hierarchical Colored Petri Net

The traditional hazard analysis approaches applied to the socio-technical system cannot cover the complex organization structures, the interactions between systems and human behaviors, the interrelated factors among sub-systems and the safety culture of specific societies. This paper presents an integrated hazard identification approach named System-Theoretic Process Analysis Based on Formalization Model (BFM-STPA), which can solve the above issues. Firstly, the hierarchical control structure models of the socio-technical system are established through Colored Petri Nets (CPN) due to its strong description ability and executable ability, which may also be regarded as the graphical system specification. Secondly, the hazards can be identified according to the CPN models following a series of guide conditions. Thirdly, the comprehensive contributing factors to the hazards will be found out by tracing the former states within the reachability graph generated from CPN model. Finally, an integrated hazard log can be derived for further hazard analysis and safety-guided design. In this paper, the above method was applied in the Chinese Train Control System level 3 (CTCS-3). And the process of hazard identification for the scenario of Temporary Speed Restriction issued was elaborated in detail. Compared with the hazard log generated by Hazard and Operability (HAZOP), the hazard log generated by BFM-STPA covered not only the subsystem failures, but also the deviation of interactions among subsystems from design intent, human errors and socio-technical drawbacks related to the TSR Issued scenario of CTCS-3.

Colored Petri net model for significant reduction of invariants in flexible manufacturing systems

This study focuses on simplification of the Petri net model of a manufacturing system for reduction in the total number of elementary circuits to decrease the analysis time of systems during investigations. A flexible manufacturing system with a tool sharing environment has been developed and investigated using colored Petri nets. The proposed model is extended and implemented on large flexible manufacturing systems (FMSs) having multiple machines and tools. The main objective of this study is to reduce the resultant invariants, as the addition of parts, machines, and tools in black token Petri net models exponentially increases the resultant invariants. Various scenarios have been investigated and compared using the developed model. The structure of the developed colored Petri net (CPN) model allows grouping of the tools that reduces the total number of places in the model. Therefore, it is evident that the developed CPN model reduces the resultant invariant that results in reduced complexity of the system.

Scenario-based system design with colored Petri nets: an application to train control systems

For the goal of model-based system software development, this paper exploits the formalism of colored Petri nets (CPNs) to design complex systems based on scenarios. The specification of UML sequence diagrams which are easily understood by customers, requirement engineers and software developers are adopted to represent scenarios as specification models. A scenario is a partial description of the system behavior, describing how users, system components and the environment interact. Thus scenarios need to be synthesized in order to obtain an overall system behavior. A large number of works (e.g., Whittle and Schumann in Proceedings of the 2000 international conference on software engineering, pp 314---323, 2000; Elkoutbi and Keller in Application and theory of Petri nets, 2000; Damas et al. in Proceedings of the 14th ACM SIGSOFT international symposium on foundations of software engineering, pp 197---207, 2000; Uchitel et al. in IEEE Trans Softw Eng 29(2):99---115, 2003) have investigated scenario synthesis providing approaches or algorithms. These synthesis approaches and algorithms result in either Petri net models (e.g., Elkoutbi and Keller 2000; Ameedeen and Bordbar in 12th international IEEE enterprise distributed object computing conference (EDOC), pp 213---221, 2008) that are mainly suitable for scenario validation or other forms of behavior models (e.g., labeled transition systems in Damas et al. 2000; Uchitel et al. 2003 and statecharts in Kruger et al. in Distributed and parallel embedded systems, pp 61---71, 1999; Whittle et al. 2000) that may be regarded as design models. Petri nets are well known for describing distributed and concurrent complex systems. Furthermore, numerous techniques, e.g., simulation, testing, state space-based techniques, structural methods and model checking, are currently available for analyzing Petri net models. Therefore, design models in the form of Petri nets, integrating all scenarios into a coherent whole and fitting for further detailed design, are promising. To this end, we present a top-down approach to establish hierarchical CPNs in accordance with specified scenarios (i.e., sequence diagrams). This approach makes use of explicitly labeling component states in the sequence diagrams to correlate scenarios. In addition, the techniques of state space analysis and ASK-CTL model checking are used to verify the correctness and consistency of the CPN model with respect to standard and system-specific properties. As the inspiration of the presented approach derives from the development of train control systems, we present an running example of designing the on-board subsystem of a satellite-based train control system to show the feasibility of our approach.

Complex Event Processing Modeling by Prioritized Colored Petri Nets

Complex event processing (CEP) is a technology that allows us to process and correlate large volumes of data by using event patterns, aiming at promptly detecting specific situations that could require special treatment. The event types and event patterns for a particular application domain are implemented by using an event processing language (EPL). Although some current model-driven tools allow end users to easily define these patterns, which are then transformed automatically into a particular EPL, the generated code is syntactically but not semantically validated. To deal with this problem, a prioritized colored Petri net (PCPN) model for CEP is proposed and conducted in this paper. This well-known graphical formalism together with CPNTools makes possible the modeling, simulation, analysis, and semantic validation of complex event-based systems. To illustrate this approach, a case study is presented, as well as a discussion on the benefits from using PCPN for modeling CEP-based systems.

Colored petri net modeling of small interfering RNA-mediated messenger RNA degradation.

Background:Mathematical modeling of biological systems is an attractive way for studying complex biological systems and their behaviors. Petri Nets, due to their ability to model systems with various levels of qualitative information, have been wildly used in modeling biological systems in which enough qualitative data may not be at disposal. These nets have been used to answer questions regarding the dynamics of different cell behaviors including the translation process. In one stage of the translation process, the RNA sequence may be degraded. In the process of degradation of RNA sequence, small-noncoding RNA molecules known as small interfering RNA (siRNA) match the target RNA sequence. As a result of this matching, the target RNA sequence is destroyed.Materials and Methods:In this context, the process of matching and destruction is modeled using Colored Petri Nets (CPNs). The model is constructed using CPNs which allow tokens to have a value or type on them. Thus, CPN is a suitable tool to model string structures in which each element of the string has a different type. Using CPNs, long RNA, and siRNA strings are modeled with a finite set of colors. The model is simulated via CPN Tools.Results:A CPN model of the matching between RNA and siRNA strings is constructed in CPN Tools environment.Conclusion:In previous studies, a network of stoichiometric equations was modeled. However, in this particular study, we modeled the mechanism behind the silencing process. Modeling this kind of mechanisms provides us with a tool to examine the effects of different factors such as mutation or drugs on the process.

Application of Coloured Petri Nets for Verification of Scenario Control Structures in UCM Notation

The article presents a method for the analysis and verification of Use Case Map (UCM) models with scenario control structures—protected components and failure handling constructs. UCM models are analyzed and verified with the help of colored Petri nets (CPN) and the SPIN model checker. Algorithms for translating UCM scenario control structures into CPN and CPN into SPIN input language Promela are described. The number of elements of the resulting CPN model and the number of Promela model states are estimated. The presented algorithm and the verification process are illustrated by the study of a network router firmware update.