Results 11  20
of
331
Bisimulation for higherorder process calculi
 INFORMATION AND COMPUTATION
, 1996
"... A higherorder process calculus is a calculus for communicating systems which contains higherorder constructs like communication of terms. We analyse the notion of bisimulation in these calculi. We argue that both the standard definition of bisimulation (i.e., the one for CCS and related calculi), ..."
Abstract

Cited by 65 (5 self)
 Add to MetaCart
A higherorder process calculus is a calculus for communicating systems which contains higherorder constructs like communication of terms. We analyse the notion of bisimulation in these calculi. We argue that both the standard definition of bisimulation (i.e., the one for CCS and related calculi), as well as higherorder bisimulation [E. Astesiano,
Comparative branchingtime semantics for Markov chains
 Information and Computation
, 2003
"... This paper presents various semantics in the branchingtime spectrum of discretetime and continuoustime Markov chains (DTMCs and CTMCs). Strong and weak bisimulation equivalence and simulation preorders are covered and are logically characterised in terms of the temporal logics PCTL (Probabilisti ..."
Abstract

Cited by 64 (17 self)
 Add to MetaCart
(Show Context)
This paper presents various semantics in the branchingtime spectrum of discretetime and continuoustime Markov chains (DTMCs and CTMCs). Strong and weak bisimulation equivalence and simulation preorders are covered and are logically characterised in terms of the temporal logics PCTL (Probabilistic Computation Tree Logic) and CSL (Continuous Stochastic Logic). Apart from presenting various existing branchingtime relations in a uniform manner, this paper presents the following new results: (i) strong simulation for CTMCs, (ii) weak simulation for CTMCs and DTMCs, (iii) logical characterizations thereof (including weak bisimulation for DTMCs), (iv) a relation between weak bisimulation and weak simulation equivalence, and (v) various connections between equivalences and preorders in the continuous and discretetime setting. The results are summarized in a branchingtime spectrum for DTMCs and CTMCs elucidating their semantics as well as their relationship. Key Words: comparative semantics, Markov chain, (weak) simulation, (weak) bisimulation, temporal logic
YAWL: Yet Another Workflow Language
, 2003
"... Based on a rigorous analysis of existing workflow management systems and workflow languages, a new workflow language is proposed: YAWL (Yet Another Workflow Language). To identify the differences between the various languages, we have collected a fairly complete set of workflow patterns. Based on th ..."
Abstract

Cited by 54 (2 self)
 Add to MetaCart
Based on a rigorous analysis of existing workflow management systems and workflow languages, a new workflow language is proposed: YAWL (Yet Another Workflow Language). To identify the differences between the various languages, we have collected a fairly complete set of workflow patterns. Based on these patterns we have evaluated several workflow products and detected considerable differences in their ability to capture control flows for nontrivial workflow processes. Languages based on Petri nets perform better when it comes to statebased workflow patterns. However, some patterns (e.g. involving multiple instances, complex synchronisations or nonlocal withdrawals) are not easy to map onto (highlevel) Petri nets. This inspired us to develop a new language by taking Petri nets as a starting point and adding mechanisms to allow for a more direct and intuitive support of the workflow patterns identified. This paper motivates the need for such a language, specifies the semantics of the language, and shows that soundness can be verified in a compositional way. Although YAWL is intended as a complete workflow language, the focus of this paper is limited to the controlflow perspective.
Workflow Modeling for Virtual Processes: an OrderPreserving ProcessView Approach
, 2002
"... Conducting workflow management allows virtual enterprises to collaboratively manage business processes. Given the diverse requirements of the participants involved in a business process, providing various participants with adequate process information is critical to effective workflow management. Th ..."
Abstract

Cited by 53 (0 self)
 Add to MetaCart
Conducting workflow management allows virtual enterprises to collaboratively manage business processes. Given the diverse requirements of the participants involved in a business process, providing various participants with adequate process information is critical to effective workflow management. This work describes a novel processview, i.e., an abstracted process which is derived from a base process to provide process abstraction, for modeling a virtual workflow process. The proposed processview model enhances the conventional activitybased process models by providing different participants with various views of a process. Moreover, this work presents a novel orderpreserving approach to derive a processview from a base process. The approach proposed herein can preserve the original ordering of activities in the base process. Additionally, a formal model is presented to define an orderpreserving processview. Finally, an algorithm is proposed for automatically generating an orderpreserving processview. The proposed approach increases the flexibility and functionality of workflow management systems.
Choreography and Orchestration: a synergic approach for system design
 In Proc. of 4th International Conference on Service Oriented Computing (ICSOC
, 2005
"... Abstract. Choreography and orchestration languages deal with business processes design and specification. Referring to Web Services technology, the most credited proposals are WSCDL about choreography and WSBPEL about orchestration. A closer look to such a kind of languages highlights two distinct ..."
Abstract

Cited by 52 (10 self)
 Add to MetaCart
(Show Context)
Abstract. Choreography and orchestration languages deal with business processes design and specification. Referring to Web Services technology, the most credited proposals are WSCDL about choreography and WSBPEL about orchestration. A closer look to such a kind of languages highlights two distinct approaches for system representation and management. Choreography describes the system in a top view manner whereas orchestration focusses on single peers description. In this paper we define a notion of conformance between choreography and orchestration which allows to state when an orchestrated system is conformant to a given choreography. Choreography and orchestration are formalized by using two process algebras and conformance takes the form of a bisimulationlike relation. 1
Invariants in Process Algebra with Data
, 1993
"... We provide rules for calculating with invariants in process algebra with data, and illustrate these with examples. The new rules turn out to be equivalent to the well known Recursive Specification Principle which states that guarded recursive equations have at most one solution. In the setting with ..."
Abstract

Cited by 50 (21 self)
 Add to MetaCart
We provide rules for calculating with invariants in process algebra with data, and illustrate these with examples. The new rules turn out to be equivalent to the well known Recursive Specification Principle which states that guarded recursive equations have at most one solution. In the setting with data this is reformulated as `every convergent linear process operator has at most one fixed point' (CLRSP). As a consequence, one can carry out verifications in wellknown process algebras satisfying CLRSP using invariants.
On measuring process model similarity based on highlevel change operations
 In ER ’08
, 2008
"... Abstract. For various applications there is the need to compare the similarity between two process models. For example, given the asis and tobe models of a particular business process, we would like to know how much they differ from each other and how we can efficiently transform the asis to the ..."
Abstract

Cited by 49 (21 self)
 Add to MetaCart
(Show Context)
Abstract. For various applications there is the need to compare the similarity between two process models. For example, given the asis and tobe models of a particular business process, we would like to know how much they differ from each other and how we can efficiently transform the asis to the tobe model; or given a running process instance and its original process schema, we might be interested in the deviations between them (e.g. due to adhoc changes at instance level). Respective considerations can be useful, for example, to minimize the efforts for propagating the schema changes to other process instances as well. All these scenarios require a method to measure the similarity or distance between two process models based on the efforts for transformation. In this paper, we provide an approach using digital logic to evaluate the distance and similarity between two process models based on highlevel change operations (e.g. to add, delete or move activities). In this way, we can not only guarantee that the transformation results in a sound process model, but also ensure that the efforts are minimized. 1
LifeCycle Inheritance  A PetriNetBased Approach
 Application and Theory of Petri Nets 1997, volume 1248 of Lecture Notes in Computer Science
, 1997
"... . Inheritance is one of the key issues of objectorientation. The inheritance mechanism allows for the definition of a subclass which inherits the features of a specific superclass. This means that methods and attributes defined for the superclass, are also available for objects of the subclass. ..."
Abstract

Cited by 47 (16 self)
 Add to MetaCart
. Inheritance is one of the key issues of objectorientation. The inheritance mechanism allows for the definition of a subclass which inherits the features of a specific superclass. This means that methods and attributes defined for the superclass, are also available for objects of the subclass. Existing methods for objectoriented modeling and design, abstract from the dynamic behavior of objects when defining inheritance. Nevertheless, it would be useful to have a mechanism which allows for the inheritance of dynamic behavior. This paper describes a Petrinet based approach to the formal specification and verification of this type of inheritance. We use Petri nets to specify the dynamics of an object class. The Petrinet formalism allows for a graphical representation of the life cycle of objects which belong to a specific object class. Four possible inheritance relations are defined. These inheritance relations can be verified automatically. Moreover, four powerful transfo...
Deciding BisimulationLike Equivalences with FiniteState Processes
, 1999
"... We show that characteristic formulae for nitestate systems up to bisimulationlike equivalences (e.g., strong and weak bisimilarity) can be given in the simple branchingtime temporal logic EF. Since EF is a very weak fragment of the modal µcalculus, model checking with EF is decidable for many mo ..."
Abstract

Cited by 46 (16 self)
 Add to MetaCart
(Show Context)
We show that characteristic formulae for nitestate systems up to bisimulationlike equivalences (e.g., strong and weak bisimilarity) can be given in the simple branchingtime temporal logic EF. Since EF is a very weak fragment of the modal µcalculus, model checking with EF is decidable for many more classes of infinitestate systems. This yields a general method for proving decidability of bisimulationlike equivalences between infinitestate processes and finitestate ones. We apply this method to the class of PAD processes, which strictly subsumes PA and pushdown (PDA) processes, showing that a large class of bisimulationlike equivalences (including, e.g., strong and weak bisimilarity) is decidable between PAD and finitestate processes. On the other hand, we also demonstrate that no `reasonable' bisimulationlike equivalence is decidable between stateextended PA processes and finitestate ones. Furthermore, weak bisimilarity with finitestate processes is shown to be undecidable even for state...
Automated Compositional Markov Chain Generation for a PlainOld Telephone System
 SCIENCE OF COMPUTER PROGRAMMING
, 1999
"... Obtaining performance models, like Markov chains and queueing networks, for systems of significant complexity and magnitude is a di#cult task that is usually tackled using human intelligence and experience. This holds in particular for performance models of a highly irregular nature. In this paper w ..."
Abstract

Cited by 45 (25 self)
 Add to MetaCart
(Show Context)
Obtaining performance models, like Markov chains and queueing networks, for systems of significant complexity and magnitude is a di#cult task that is usually tackled using human intelligence and experience. This holds in particular for performance models of a highly irregular nature. In this paper we argue by means of a nontrivial example  a plainold telephone system (POTS)  that a stochastic extension of process algebra can diminish these problems by permitting an automatic generation of Markov chains. We introduce a stochastic process algebra that separates the advance of time and action occurrences. For the sake of specification convenience we incorporate an elapse operator that allows the modular description of time constraints where delays are described by continuous phasetype distributions. Using this language we provide a formal specification of the POTS and show how a stochastic process of more than 10 7 states is automatically obtained from this system description. ...