Simplifying the verification of simulation models through Petri net to FlexSim mapping

Simplifying the encoding of a simulation conceptual model representation reduces the number of errors that will be detected in the verification phase. In this paper, we present a mapping between Petri nets, a well-known formalism, and FlexSim, a well-known simulation tool. The proposal is illustrated through an example of how a model specified in a Petri net can be encoded easily, reducing the time needed to understand and verify the model. In the proposed methodology, the mapping must be defined at the initial stage of the encoding, starting from (in this case) a Petri net conceptual model, and ending at the encoding tool (FlexSim in this case). The main advantages of the proposed methodology are discussed.Peer ReviewedPostprint (author's final draft

Business process modeling and simulation

The textbook provides the essentials of the Business Process (BP) Modeling and Simulation (M&S) from the verbal BP description to the formulation of the mathematical scheme of the model and the simulation program. Both the analytical modeling and the simulation approaches to BP M&S are considered. Special attention is given to the theoretical and practical aspects of the BP M&S. The text covers the following topics: fundamentals of the BP M&S, conceptual modeling using IDEF3 standard, cost metrics and the activity based costing, analytical modeling (queuing networks, linear and dynamic programming), simulation with GPSS, timed Petri Nets, and Crystal Ball toolkits. Case studies include BP simulations with BPwin and GPSS. The intended readers are senior graduate students and junior postgraduate students of computer science and industrial management

Modelling and Simulation of Queuing Models through the concept of Petri Nets

In recent years Petri Nets has been in demand due to its visual depiction. Petri Nets are used as an effective method for portraying synchronization, a concurrency between different system activities. In queuing models Petri networks are used to represent distributed modeling of the system and thus evaluate their performance. By specifying suitable stochastic Petri Nets models, the authors concentrate on representing multi-class queuing systems of various queuing disciplines. The key idea is to define SPN models that simulate a given queue discipline 's behavior with some acceptable random choice. Authors have find system queuing with both a single server and multiple servers with load-dependent service rate. Petri networks in the queuing model have enhanced scalability by combining queuing and modeling power expressiveness of 'petri networks.' Examples of application of SPN models to performance evaluation of multiprocessor systems demonstrate the utility and effectiveness of this modeling method. In this paper, authors have made use of Stochastic Petri nets in queuing models to evaluate the performance of the system

Data-aware Soundness Verification and Repair of Data Petri-Nets

openBusiness processes are one of organizations' core assets, impacting directly on the quality of products and services and on the revenue of corporations. A failure in such processes can negatively affect the core of the organization and its production chain. For such reasons, various tools, techniques, and methods have been gathered from different disciplines and collected in what is called Business Process Management (BPM). Petri Net, or Place/Transition (P/T) Net, is one such tool: it is a powerful modeling formalism combining a well-defined mathematical theory with a graphical representation of the dynamic behavior of systems. Given the endless heterogeneity of cases and the extensive combinations between the various resources that interact in a process, additional Petri Net extensions were designed through the years, each aiming to provide more expressive power to describe a broader range of systems. One is Data Petri Net (DPN). This Petri Net-based modeling formalism allows adding a data dimension to the traditional control flow, which permits both the description of how data evolve through the lifecycle of the process and the decisions based on such data. The presence of unreachable activities or steps without the possibility to proceed further falls under the concept of soundness, and its verification has been a central topic for different research activities. The following work hooks into soundness verification and provides an approach to repair Data Petri Nets concerning data and decision perspective. It provides an extensive and accurate description of unsound DPNs that helps the reader understand the base cases and their resolution. Due to the presence of false-positive cases within the existing soundness verification techniques in the literature, this work studies such issues and proposes a patch aimed at the correct identification of these unsound DPNs. The verification and repair techniques rely on the Constraint Graph structure, a finite symbolic abstraction of the possibly infinite traces of a DPN.The algorithms proposed assume that the underlying Petri Net is sound, thus focusing solely on the repair of data that determines the behavior of the net, aiming to restore its soundness. They seek to provide a solution with minimal changes from the original DPN, which helps the process designer verify its correctness and plan further developments and optimizations.Business processes are one of organizations' core assets, impacting directly on the quality of products and services and on the revenue of corporations. A failure in such processes can negatively affect the core of the organization and its production chain. For such reasons, various tools, techniques, and methods have been gathered from different disciplines and collected in what is called Business Process Management (BPM). Petri Net, or Place/Transition (P/T) Net, is one such tool: it is a powerful modeling formalism combining a well-defined mathematical theory with a graphical representation of the dynamic behavior of systems. Given the endless heterogeneity of cases and the extensive combinations between the various resources that interact in a process, additional Petri Net extensions were designed through the years, each aiming to provide more expressive power to describe a broader range of systems. One is Data Petri Net (DPN). This Petri Net-based modeling formalism allows adding a data dimension to the traditional control flow, which permits both the description of how data evolve through the lifecycle of the process and the decisions based on such data. The presence of unreachable activities or steps without the possibility to proceed further falls under the concept of soundness, and its verification has been a central topic for different research activities. The following work hooks into soundness verification and provides an approach to repair Data Petri Nets concerning data and decision perspective. It provides an extensive and accurate description of unsound DPNs that helps the reader understand the base cases and their resolution. Due to the presence of false-positive cases within the existing soundness verification techniques in the literature, this work studies such issues and proposes a patch aimed at the correct identification of these unsound DPNs. The verification and repair techniques rely on the Constraint Graph structure, a finite symbolic abstraction of the possibly infinite traces of a DPN.The algorithms proposed assume that the underlying Petri Net is sound, thus focusing solely on the repair of data that determines the behavior of the net, aiming to restore its soundness. They seek to provide a solution with minimal changes from the original DPN, which helps the process designer verify its correctness and plan further developments and optimizations

Formal Approach Based on Petri Nets for Modeling and Verification of Video Games

Video games are complex systems that combine technical and artistic processes. The specification of this type of system is not a trivial task, making it necessary to use diagrams and charts to visually specify sets of requirements. Therefore, the underlying proposal of this work is to present an approach based on the formalism of Petri nets for aiding in the design process of video games. The activities of the game are represented by a specific type of Petri net called WorkFlow net. The definition of a topological map can be represented by state graphs. Using Colored Petri nets, it is possible to define formal communication mechanisms between the model of activity and the model of the map. The simulation of the timed models allows then to produce an estimated time that corresponds to the effective duration a player will need to complete a level of a game. Furthermore, a kind of Soundness property related to gameplay in a game Quest can be verified through state space analysis. For a better understanding of the approach, the video game Silent Hill II is used

Repairing Process Models with Non-Free-Choice Constructs Based on Token Replay

A method of repairing process models with non-free-choice constructs is proposed based on logical Petri nets, aiming at the problem of low precision in the existing repair methods. An extended successor matrix of transitions is determined according to the distance between any two transitions. There are two types of choice-construct transitions. One is a non-free-choice construct transition, and the other is a general choice construct transition. The type of choice-construct transitions can be determined based on the extended successor matrix and the relationship between the front and back sets of transitions. The location of the deviations is calculated by an improved replaying method. Finally, a model can be repaired according to remaining-token places and missing-token places. Based on the experiments on real event logs, the method proposed in this paper has a better performance in fitness, precision, and simplicity compared with its peers

Iterchanging Discrete Event Simulationprocess Interaction Modelsusing The Web Ontology Language - Owl

Discrete event simulation development requires significant investments in time and resources. Descriptions of discrete event simulation models are associated with world views, including the process interaction orientation. Historically, these models have been encoded using high-level programming languages or special purpose, typically vendor-specific, simulation languages. These approaches complicate simulation model reuse and interchange. The current document-centric World Wide Web is evolving into a Semantic Web that communicates information using ontologies. The Web Ontology Language OWL, was used to encode a Process Interaction Modeling Ontology for Discrete Event Simulations (PIMODES). The PIMODES ontology was developed using ontology engineering processes. Software was developed to demonstrate the feasibility of interchanging models from commercial simulation packages using PIMODES as an intermediate representation. The purpose of PIMODES is to provide a vendor-neutral open representation to support model interchange. Model interchange enables reuse and provides an opportunity to improve simulation quality, reduce development costs, and reduce development times