Showing papers on "Process architecture published in 1993"
Book•
30 Sep 1993
TL;DR: This work introduces Petri nets, a model for manufacturing information systems, and some net subclasses and their analysis, as well as hybrid synthesis: combining top-down and bottom-up methods.
Abstract: Introduction. 1: Introducing Petri nets M. Silva. Nets and net systems. On modelling features. On net systems interpretations. Approaching concurrency qualitative problems. Qualitative analysis of net system models. Some net subclasses and their analysis. Concluding remarks. 3: Principles of system modelling J.M. Proth. Manufacturing system modelling: basic concepts. Transportation system between two points on a shop-floor. Storage facilities. Operation modelling. Tool systems. Material-handling systems. Conclusion. 3: Synthesis for manufacturing systems integration F. DiCesare, Mu Der Jeng. Introduction to Synthesis. Bottom-up synthesis. Top-down methods. Hybrid synthesis: combining top-down and bottom-up. Summary. 4: Performance evaluation of manufacturing systems J.M. Proth. Introduction. Event graphs: definition and properties. Manufacturing systems working on a cyclic basis. The general case. 5: Petri nets for manufacturing information systems G. Harhalakis, F.B. Vernadat. Introduction. Basics of manufacturing information systems. High-level Petri nets. Organization analysis and conceptual database design. Modeling, analysis and implementation of company policies. Conclusions. Index.
337 citations
TL;DR: The class of Petri nets obtained by eliminating timing from generalized stochastic Petri net (GSPN) models while preserving the qualitative behavior is identified and it is shown that for a (wide) class of nets, the definition of firing probabilities of conflicting immediate transitions does not require the information on reachable markings.
Abstract: The class of Petri nets obtained by eliminating timing from generalized stochastic Petri net (GSPN) models while preserving the qualitative behavior is identified. Structural results for those nets are derived, obtaining the first structural analysis of Petri nets with priority and inhibitor arcs. A revision of the GSPN definition based on the structural properties of the models is presented. It is shown that for a (wide) class of nets, the definition of firing probabilities of conflicting immediate transitions does not require the information on reachable markings. Identification of the class of models for which the net-level specification is possible is also based on the structural analysis results. The procedure for the model specification is illustrated by means of an example. It is also shown that a net-level specification of the model associated with efficient structural analysis techniques can have a substantial impact on model analysis. >
255 citations
19 Oct 1993
TL;DR: It is shown that efficient analysis techniques from PetriNet theory can be exploited for analysis of QPNs, thus supporting the general objective of combining Petri net and queueing network formalisms.
Abstract: System analysis is often needed with respect to both qualitative and quantitative aspects. In recent decades, several formalisms have been developed that attempt to combine these aspects in one description. Present emphasis is on stochastic Petri nets. One disadvantage of these formalisms is the difficulties when describing scheduling strategies with Petri net elements. A new version of queuing Petri nets (QPNs), which combines queuing networks and Petri nets, aiming at eliminating these disadvantages is described. The new version also exhibits the modeling of timed transitions and timeless queues for describing pure scheduling mechanisms. QPNs are a superset of queueing networks and (generalized stochastic) Petri nets. The analysis of QPNs is discussed, and it is shown that efficient analysis techniques from Petri net theory can be exploited for analysis of QPNs, thus supporting the general objective of combining Petri net and queueing network formalisms. >
170 citations
01 Jun 1993
TL;DR: In this article, the basic theoretical aspects of Coloured Petri Nets (CP-nets or CPN) are presented, from a promising theoretical model, to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems.
Abstract: This paper presents the basic theoretical aspects of Coloured Petri Nets (CP-nets or CPN). CP-nets have been developed, from being a promising theoretical model, to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and/or computers communicate by means of some more or less formal rules). The paper contains the formal definition of CP-nets and their basic concepts (e.g., the different dynamic properties such as liveness and fairness). The paper also contains a short introduction to the analysis methods, in particular occurrence graphs and place invariants.
142 citations
01 Mar 1993
TL;DR: The modeling and analysis of a flexible manufacturing system (FMS) cell using Petri nets is presented and theAnalysis of a timed Petri net for cycle time is presented.
Abstract: The modeling and analysis of a flexible manufacturing system (FMS) cell using Petri nets is presented. In order to illustrate how a Petri net with desirable properties can be constructed, the detailed synthesis process for this cell is described. During the process, top-down refinement, system decomposition, and modular composition ideas are used to achieve the hierarchy and preservation of important system properties. These properties include liveness, boundedness/safeness, and reversibility that guarantee the system to operate in a stable, deadlock-free, and cyclic manner. Furthermore, the analysis of a timed Petri net for cycle time is presented. The timed Petri net is first converted into an equivalent timed marked graph by a reduction technique. Then the standard procedure to find the cycle time for marked graphs is applied. >
122 citations
TL;DR: Two Petri net structures capable of enforcing generalized mutual exclusion constraints on place/transition nets with uncontrollable transitions are presented, a monitor-based solution and a supervisory based solution.
62 citations
21 Jun 1993
TL;DR: This work uses the client/server example to illustrate the G-Net specification of distributed systems, and how such a specification can be translated into a Predicate/Transition net for formal analysis.
Abstract: We present a Petri net based framework called G-Net for the modular design of complex information systems. The motivation of this framework is to integrate Petri net theory with a modular, objectoriented approach for the specification and prototyping of complex software systems. We use the client/server example to illustrate the G-Net specification of distributed systems, and how such a specification can be translated into a Predicate/Transition net for formal analysis. The differences between G-Net and hierarchical Petri net, as well as some limitations of the transformation technique, are then discussed.
56 citations
TL;DR: Distributed simulations of timed transition Petri nets on real multiprocessor systems can be faster than sequential simulation, even for small simulation models, the authors show.
Abstract: Distributed simulations of timed transition Petri nets on real multiprocessor systems can be faster than sequential simulation, even for small simulation models. The authors show how. >
52 citations
08 Jun 1993
TL;DR: An overview of the benefits that can be expected from the use of the PNO formalism in dialogue modelling is presented, and a detailed example illustrates the application of this method.
Abstract: This paper presents a survey of three formalisms that are used for modelling the dialogue of user-driven interfaces: state diagrams, events and Petri nets. Petri nets are found to be the best suited formalism in this area, even if they lack structure. In order to address this problem, the usefulness of the object-oriented approach is discussed, and we present a formalism, called Petri Nets with Objects (PNO), that integrates both object-oriented and Petri nets approaches. A three-step method for building such models, consisting in defining the object classes, definiting the presentation and modelling the application's dialogue, is presented, and a detailed example illustrates the application of this method. Finally, we present an overview of the benefits that can be expected from the use of the PNO formalism in dialogue modelling.
51 citations
19 Oct 1993
TL;DR: An interesting application of the operational laws to the statement and the efficient solution of problems related to the estimation of performance bounds insensitive to the timing probability distributions is shown.
Abstract: Operational analysis techniques are used to partially characterize the behavior of timed Petri nets under very weak assumptions on their timing semantics. New operational inequalities are derived that are typical of the presence of synchronization and that were therefore not considered in queuing network models. An interesting application of the operational laws to the statement and the efficient solution of problems related to the estimation of performance bounds insensitive to the timing probability distributions is shown. The results obtained generalize and improve in a clear setting results that were derived in the last few years for several different subclasses of timed Petri nets. In particular, the extension to well-formed colored nets appears straightforward and allows an efficient exploitation of model symmetries. >
21 Jun 1993
TL;DR: The client- server protocol promoted by the object-oriented approach to Petri nets is adapted, and the possibility to compose client-server nets while preserving the nets' language and liveness is studied.
Abstract: Modelling the behavior of a system as a set of cooperating nets requires to define a high-level communication protocol which takes into account the very nature of their interactions This paper proposes to adapt the client-server protocol promoted by the object-oriented approach to Petri nets, and to compose Petri nets according to this protocolThis protocol relies upon four basic rules which assert the honesty and discretion of clients and servers A class of nets respecting these rules, called clientserver nets, is defined, as is the composition of these nets according to a Use function The possibility to compose client-server nets while preserving the nets' language and liveness is studied This possibility comes down to very simple relationships between the main characteristics of client-server nets: the demand and the confidence degree as a client, and the supply and the reliability degree as a server These relationships are preserved by the composition of nets, so the client-server protocol allows for the incremental design of systems and favors the reuse of nets
21 Jun 1993
TL;DR: This work systematically investigates the interdependencies among the DDES strategy (conservative, Time Warp) and the spatial decomposition of TTPNs into logical processes to be run concurrently on individual processing nodes in a message passing and shared memory multiprocessor environment.
Abstract: The conservative and the optimistic approaches of distributed discrete event simulation (DDES) are used as the starting point to develop an optimized simulation framework for studying the behaviour of large and complex timed transition Petri net (TTPN) models. This work systematically investigates the interdependencies among the DDES strategy (conservative, Time Warp) and the spatial decomposition of TTPNs into logical processes to be run concurrently on individual processing nodes in a message passing and shared memory multiprocessor environment. Partitioning heuristics are developed taking into account the structural properties of the TTPN model, and the simulation strategy is tuned accordingly in order to attain the maximum computational speedup. Implementations of the simulation framework have been undertaken for the Intel iPSC/860 hypercube, the Sequent Balance and a Transputer based multiprocessor. The simulation results show that the use of the Petri net formalism allows an automatic extraction of the parallelism and causality relations inherent to the model.
Journal Article•
TL;DR: In this paper, the Petri net formalism is used for developing modular models of flexible manufacturing systems (FMS) and the resulting Petri nets serve as a simulation tool for scheduling optimisation.
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TL;DR: This model, an extension of the hybrid Petri nets, allows one to integrate a formalisation of parts circulation on accumulation conveyors and is defined with the introduction of a new kind of place and transition: the batch place and batch transition.
Abstract: This paper presents a new type of Petri nets, batches Petri nets. This model, an extension of the hybrid Petri nets, allows one to integrate a formalisation of parts circulation on accumulation conveyors. The batches Petri net is defined with the introduction of a new kind of place and transition: the batch place and batch transition. Evolution rules are determined in order to do the simulation of systems composed by accumulation phenomena. >
30 Aug 1993
TL;DR: Completeness is shown for several versions of Girard's linear logic with respect to Petri nets as the class of models, enabling descriptions of the kinds of properties one might wish to show of nets.
Abstract: Completeness is shown for several versions of Girard's linear logic with respect to Petri nets as the class of models The strongest logic considered is intuitionistic linear logic, with ⊗, ⊸, &, ⊕ and the exponential ! (“of course”), and forms of quantification This logic is shown sound and complete with respect to atomic nets (these include nets in which every transition leads to a nonempty multiset of places) The logic is remarkably expressive, enabling descriptions of the kinds of properties one might wish to show of nets; in particular, negative properties, asserting the impossibility of an assertion, can also be expressed
TL;DR: This work gives the first comprehensive complexity analysis of a class of potentially unbounded Petri nets defined in terms of their behavior, and argues that although neither normal nor sinkless Petrinets are strictly more powerful than persistentPetri nets, they nonetheless are both capable of modeling a more interesting class of problems.
TL;DR: The formal semantics of a prototyping language for hard real-time systems, PSDL, is given, which provides a data flow notation augmented by application-orientation timing and control constraints to describe a system as a hierarchy of networks of processing units communicating via data streams.
Abstract: The formal semantics of a prototyping language for hard real-time systems, PSDL, is given. PSDL provides a data flow notation augmented by application-orientation timing and control constraints to describe a system as a hierarchy of networks of processing units communicating via data streams. The semantics of PSDL are defined in terms of algebraic high-level Petri nets. This formalism combines algebraic specifications of abstract data types with process and concurrency concepts of Petri nets. Its data abstraction facilities are used to define the meaning of PSDL data types, while high-level Petri nets serve to model the casual and timing behavior of a system. The net model exposes potential concurrency of computation and makes all synchronization needs implied by timing and control constraints explicit and precise. Time is treated as state of clocks, and clocks are modeled as ordinary system components. The net semantics provides the basis for applying analysis techniques and semantic tools available for high-level Petri nets. >
01 Jun 1993
TL;DR: This article shows how individual Petri nets form models of Girard's intuitionistic linear logic, and explores questions of expressiveness and completeness of linear logic with respect to this interpretation.
Abstract: This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some appraisal of the value of linear logic as a specification logic for Petri nets. This article might serve as a tutorial, providing one in-road into Girard's linear logic via Petri nets. With this in mind we have added several exercises and their solutions. We have made no attempt to be exhaustive in our treatment, dedicating our treatment to one semantics of intuitionistic linear logic.
TL;DR: The paper shows how entity-relationship diagrams and high-level Petri nets can system-atically be synthesized into rigorous, yet graphic system models which meet the requirements of conceptual modeling.
02 May 1993
TL;DR: A conflict-based method is proposed to decompose the control problems so that a hierarchical decentralized real-time supervisor can be constructed.
Abstract: A flow optimization method for control synthesis of flexible manufacturing systems modeled by a class of controlled timed Petri nets is presented. A closed-loop control framework, which consists of a controlled Petri net model as plant and a supervisor which controls this plant, is used. This allows external control to be applied to Petri nets for modeling dynamic control strategies. A supervisor is designed using a two-level hierarchical structure: a continuous flow approximation model of a discrete-event system for the optimization of the firing frequencies of transitions in Petri nets, and a real-time firing frequency tracking controller for conflict-solving. A conflict-based method is proposed to decompose the control problems so that a hierarchical decentralized real-time supervisor can be constructed. >
28 Mar 1993
TL;DR: An approach to the fuzzification of the Petri net is proposed, where a token in the fuzzy PetriNet (FPN) is described as a membership function of a linguistic term as opposed to a single number representing a membership value.
Abstract: An approach to the fuzzification of the Petri net is proposed. A token in the fuzzy Petri net (FPN) is described as a membership function of a linguistic term as opposed to a single number representing a membership value. A transition, specified as a production rule, can be fired if the distance of input tokens from the desired values is less than a given tolerance. This distance determines the difference between the output tokens produced and the output token values specified by the transition. The FPN is an excellent modeling and knowledge representation tool for all Petri net modeling applications involving imprecise token values. >
01 Aug 1993
TL;DR: The paper describes (with reference to on-going implementation work) how CIM-OSA behaviour models can be represented and handled by stochastic time Petri net model execution tools.
Abstract: Means are considered that can structure design and building processes associated with integrated manufacturing systems. To meet the identified needs, the paper proposes the use of an environment for executing models which adopts and extends the concepts and guidelines identified by the CIM-OSA (computer integrated manufacturing-open sytems architecture) consortium.A key component of the environment concerns the execution of models of behaviour. The paper describes (with reference to on-going implementation work) how CIM-OSA behaviour models can be represented and handled by stochastic time Petri net model execution tools.The use of the design and building environment is illustrated with reference to a case study application involving the batch manufacture of a family of electronic products. Here, the necessary form of key CIM-OSA and Petri net models are described, as are results from the Petri net simulation studies. The paper also comments on the advantages and limitations of the CIM-OSA modelling appro...
TL;DR: The aim of this paper is to suggest and discuss some possible definitions of Modular Petri nets, and to introduce the concept of Petri subnet, which allows automatic composition of subnets into a larger model.
Abstract: The use of Petri nets for modelling, analysing and simulating complex distributed production systems meets serious problems when the size of the model grows. Therefore, it would be very useful to decompose a Petri net based model into smaller models linked with one another. The aim of this paper is to suggest and discuss some possible definitions of Modular Petri nets. This is accomplished by introducing the concept of Petri subnet. Two possible definitions are proposed and the meaning and the usefulness with respect to both model definition and model executability for simulation are pointed out. All definitions are given for the basic model of Petri nets. The extension of modularity concepts to high level Petri nets is shown to be possible in the second part of the paper, where an application is illustrated. In particular an algorithm is given which allows automatic composition of subnets into a larger model
01 Jan 1993
TL;DR: A design process can be seen as the process of creating a representation of the underlying object that can then be analyzed to derive important characteristics of the design process.
Abstract: Design of an object generally involves creating a formal model of the object. A design process can be seen as the process of creating a representation of the underlying object. This representation can then be analyzed to derive important characteristics of the design process.
19 Oct 1993
TL;DR: The authors solve the problem of detecting confusion in colored stochastic Petri nets and computing the equivalence classes of the structural conflict relation by relying on the symbolic representation of structural relations and the definition of operations on these symbolic relations.
Abstract: Generalized stochastic Petri nets provide the modeller with immediate transitions, but a model will be correct only if the modeller can specify how to solve the firing conflicts between these transitions. This task is usually cumbersome and may be impossible for large nets. In confusion-free nets, these conflict sets are subsets of equivalence classes of a structural conflict relation, which greatly simplifies the previous task. The authors solve the problem of detecting confusion in colored stochastic Petri nets and computing the equivalence classes of the structural conflict relation. The approach relies on two techniques: the symbolic representation of structural relations and the definition of operations on these symbolic relations. Combined with the lumping method presented by G. Chiola et al. (1991), the algorithm could be the basis of an efficient tool for the analysis of colored generalized stochastic Petri nets. >
01 Dec 1993
TL;DR: This paper proposes a more cost-effective architecture for the same purpose: SRFA, based on "shifting register files", which introduces attractive solutions for the memory contention problem in general.
Abstract: This paper presents a new technique for software pipelining using the Petri nets. Our technique called the Petri Net Pacemaker (PNP) can create near optimal pipelines with less algorithmic effort than other techniques. The pacemaker is a novel idea which exploits the behavior of Petri nets to model the problem of scheduling operations of a loop body for software pipelining. >
17 Oct 1993
TL;DR: The authors show how to enrich the coloured Petri net model so, that the object-oriented concepts can be used as the methodology and should easily be transferable to other high-level nets.
Abstract: For object-oriented specifications no techniques are available which are able to model parallel aspects. The techniques proposed up to now are all inadequate. At the same time there is no method for the use of coloured Petri nets. The authors propose to use coloured Petri nets with their known advantages for object-oriented analysis and object-oriented design to get a synergetic effect. This paper introduces an object-oriented interpretation of coloured Petri nets. The authors show how to enrich the coloured Petri net model so, that the object-oriented concepts can be used as the methodology. Only minor assumptions are made about the inscription language. The approach should easily be transferable to other high-level nets. The authors do not consider a modification of the nets. >
TL;DR: Timed Petri nets have been applied to model the production systems, and their usefulness to describe and analyze such systems has been presented, and the modelling capabilities of timed Petri net have been extended.