Stochastic Timed Petri Net Model Research Articles

An UML Based Performance Evaluation of Real-Time Systems Using Timed Petri Net

Performance is a critical non-functional parameter for real-time systems and performance analysis is an important task making it more challenging for complex real-time systems. Mostly performance analysis is performed after the system development but an early stage analysis and validation of performance using system models can improve the system quality. In this paper, we present an early stage automated performance evaluation methodology to analyse system performance using the UML sequence diagram model annotated with modeling and analysis of real-time and embedded systems (MARTE) profile. MARTE offers a performance domain sub-profile that is used for representing real-time system properties essential for performance evaluation. In this paper, a transformation technique and transformation rules are proposed to map the UML sequence diagram model into a Generalized Stochastic Timed Petri net model. All the transformation rules are implemented using a metamodel based approach and Atlas Transformation Language (ATL). A case study from the manufacturing domain a Kanban system is used for validating the proposed technique.

Stochastic timed Petri nets to dynamically design and simulate industrial production processes

Stochastic timed Petri nets are among the most effective languages to model event driven uncertain processes. Their adoption in the industrial sector is even more diffuse and of potential help for the practitioners. This paper presents a stepwise approach to support the dynamic design and simulation of manufacturing and assembly production processes. An industrial application from the white good sector, based on a semi-automatic assembly line is, further, discussed demonstrating the approach flexibility and the modelling language key strengths. The stochastic timed Petri net model for such a scenario is described together with the simulation outcomes of interest for the assembly line design and the production and maintenance activity scheduling.

Molding and Optimization of Workflow Based on Stochastic Timed Petri Nets in Customized Supply Chain Management

Customized Supply Chain Management (CSCM) has been made much account of attention in Flexible Manufacturing Systems (FSM). Products are customized by customer’s special needs at stochastic time. Then Manufacturing Oriented to Customization (MOC) would inevitably be faced by those enterprises that had to meet the changeable and complex needs of customers. However, there were large quantities of difficulties would appear in MOC supply chains, such as information overload, technology and resource constraints. All of these problems made it hard to quickly and effectively respond to customers’ needs. Therefore, we need to find a new way to deal effectively with the problems about how to respond quickly to supply chains oriented to customization. Petri Nets have been extensively used for modeling and simulating of the dynamics of flexible manufacturing systems. However, Petri Nets have not been very popular for molding of workflow in CSCM environmental. In this paper Stochastic Timed Petri Nets (STPN) were used to solve the above problems. The enterprises’ workflow was analyzed, and then the STPN model was constructed according to the characteristics of its internal supply chain. In order to minimize total tardiness time of workflow, the structure of STPN was optimized in a proper way. The results suggest that the STPN approach is also valid to minimize due date of each transition in CSCM and responses to customized needs more quickly than before.

Modeling and Analysis the Web Structure Using Stochastic Timed Petri Nets

Precise analysis of the Web structure can facilitate data pre-processing and enhance the accuracy of the mining results in the procedure of Web usage mining. STPN (Stochastic Timed Petri Nets) is a high-level graphical model widely used in modeling system activities with concurrency. STPN can save the analyzed results in an incidence matrix for future follow-up analyses, and some already-verified properties held by STPN, such as reachability, can also be used to solve some unsettled problems in the model. In the present study, we put forth the use of STPN as the Web structure model. We adopt Place in the STPN model to represent webpage on the websites and use Transition to represent hyperlink. Through the model, we can conduct Web structure analysis. We simultaneously employ the Web structure analysis information in the incidence matrix and the reachability properties, obtained from the STPN model, to help proceed with pageview identification and path completion at the data preprocessing phase.

Forward of Special Issue on “Mobile System, Agent Technology, and Web Services”

Forward of Special Issue on “Mobile System, Agent Technology, and Web Services”

STPN Model of Physical and MAC Layer of Lon Works®

LonWorks is one of the most popular fieldbus systems in building automation. It uses a MAC protocol called ‘predictive p-persistent CSMA’, which differentiates from p-persistent CSMA method by partial prediction of the channel backlog. Under optimal conditions predictive p-persistent CSMA keeps collision rate independent of the channel utilisation. | Stochastic Timed Petri Net Model of LONWORKS MAC layer and small PN extension for linking of models are presented. Some simulation results are demonstrated.

On the stochastic timed Pétri nets model and its application to the DQDB protocol

The goal of this paper is twofold : at first, to present the stochastic timed Petri nets model by emphasizing its ability to express the main characteristics of real time distributed systems (parallelism, synchronization by message exchange, time attributes and in particular time constraints) and to allow both qualitative and quantitative analysis (concept of randomized states graph); second, to show a modeling methodology based on this model that allows a rigorous modeling of theDqdb protocol (Qa access, bwb mechanism role,Pa access influence). A new contribution to theQa mechanism has been done (1).

Formulating and solving optimization problems using stochastic timed Petri nets

Stochastic Timed Petri Nets (STPNs) have been used to study the performance of various aspects of computer systems. We describe an innovative way to use these models to solve optimization problems. We outline the steps by which an STPN model can be employed to find the solution to the optimal directory placement problem.