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Process Equivalence: Comparing Two Process Models Based on Observed Behavior
 International Conference on Business Process Management (BPM 2006), volume 4102 of Lecture Notes in Computer Science
, 2006
"... Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discover ..."
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Cited by 32 (7 self)
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Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discovered using process mining techniques. Although many researchers have worked on different notions of equivalence (e.g., trace equivalence, bisimulation, branching bisimulation, etc.), most of the existing notions are not very useful in this context. First of all, most equivalence notions result in a binary answer (i.e., two processes are equivalent or not). This is not very helpful, because, in reallife applications, one needs to differentiate between slightly different models and completely different models. Second, not all parts of a process model are equally important. There may be parts of the process model that are rarely activated while other parts are executed for most process instances. Clearly, these should be considered differently. To address these problems, this paper proposes a completely new way of comparing process models. Rather than directly comparing two models, the process models are compared with respect to some typical behavior. This way we are able to avoid the two problems. Although the results are presented in the context of Petri nets, the approach can be applied to any process modeling language with executable semantics. Keywords: Process Equivalence, Petri Nets, Process Mining. 1
Quantifying Process Equivalence Based on Observed Behavior
"... Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discover ..."
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Cited by 23 (0 self)
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Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discovered using process mining techniques. Although many researchers have worked on different notions of equivalence (e.g., trace equivalence, bisimulation, branching bisimulation, etc.), most of the existing notions are not very useful in this context. First of all, most equivalence notions result in a binary answer (i.e., two processes are equivalent or not). This is not very helpful, because, in reallife applications, one needs to differentiate between slightly different models and completely different models. Second, not all parts of a process model are equally important. There may be parts of the process model that are rarely activated (i.e., “process veins”) while other parts are executed for most process instances (i.e., the “process arteries”). Clearly, differences in some veins of a process are less important than differences in the main arteries of a process. To address the problem, this paper proposes a completely new way of comparing process models. Rather than directly comparing two models, the process models are compared with respect to some typical behavior. This way, we are able to avoid the two problems just mentioned. The approach has been implemented and has been used in the context of genetic process mining. Although the results are presented in the context of Petri nets, the approach can be applied to any process modeling language with executable semantics.
Maximal Structuring of Acyclic Process Models
, 2012
"... This article addresses the transformation of a process model with an arbitrary topology into an equivalent structured process model. In particular, this article studies the subclass of process models that have no equivalent wellstructured representation but which, nevertheless, can be partially str ..."
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Cited by 5 (2 self)
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This article addresses the transformation of a process model with an arbitrary topology into an equivalent structured process model. In particular, this article studies the subclass of process models that have no equivalent wellstructured representation but which, nevertheless, can be partially structured into their maximallystructured representation. The transformations are performed under a behavioral equivalence notion which preserves the observed concurrency of tasks in equivalent process models. The article gives a full characterization of the subclass of acyclic process models that have no equivalent wellstructured representation but do have an equivalent maximallystructured one, as well as proposes a complete structuring method. Together with our previous results, this article completes the solution of the process model structuring problem for the class of acyclic process models.
Symmetric and Asymmetric Asynchronous Interaction
 ICE 2008
, 2008
"... We investigate classes of systems based on different interaction patterns with the aim of achieving distributability. As our system model we use Petri nets. In Petri nets, an inherent concept of simultaneity is built in, since when a transition has more than one preplace, it can be crucial that toke ..."
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Cited by 3 (0 self)
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We investigate classes of systems based on different interaction patterns with the aim of achieving distributability. As our system model we use Petri nets. In Petri nets, an inherent concept of simultaneity is built in, since when a transition has more than one preplace, it can be crucial that tokens are removed instantaneously. When modelling a system which is intended to be implemented in a distributed way by a Petri net, this builtin concept of synchronous interaction may be problematic. To investigate the problem we assume that removing tokens from places can no longer be considered as instantaneous. We model this by inserting silent (unobservable) transitions between transitions and their preplaces. We investigate three different patterns for modelling this type of asynchronous interaction. Full asynchrony assumes that every removal of a token from a place is time consuming. For symmetric asynchrony, tokens are only removed slowly in case of backward branched transitions, hence where the concept of simultaneous removal actually occurs. Finally we consider a more intricate pattern by allowing to remove tokens from preplaces of backward branched transitions asynchronously in sequence (asymmetric asynchrony). We investigate the effect of these different transformations of instantaneous interaction into asynchronous interaction patterns by comparing the behaviours of nets before and after insertion of the silent transitions. We exhibit for which classes of Petri nets we obtain equivalent behaviour with respect to failures equivalence. It turns out that the resulting hierarchy of Petri net classes can be described by semistructural properties. In case of full asynchrony and symmetric asynchrony, we obtain precise characterisations; for asymmetric asynchrony we obtain lower and upper bounds. We briefly comment on possible applications of our results to Message Sequence Charts.
Beyond Asymmetric Choice: A note on some extensions
, 1998
"... this paper, we explore further generalizations of asymmetric choice nets. In an asymmetric choice net, it is not allowed that two transitions compete for a token in a shared input place while they both have private input places, i.e., the input set of the first transition must be included in the inp ..."
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Cited by 3 (0 self)
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this paper, we explore further generalizations of asymmetric choice nets. In an asymmetric choice net, it is not allowed that two transitions compete for a token in a shared input place while they both have private input places, i.e., the input set of the first transition must be included in the input set of the other transition or vise versa. Clearly, free choice nets satisfy this structural property. In this paper, we extend the notion of asymmetric choice with test arcs, also called loops or self loops. If a place is both an input and an output place of a transition, the set of two arcs connecting the place and the transition is called a test arc because the transition only tests the presence of the token and does not really remove it while firing. Wewillinvestigate several alternative definitions. It turns out that allowing arbitrary test arcs in addition to the classical definition of asymmetric choice is not suitable. The most basic results do not hold for these naive extensions. Therefore, wegive a more sophisticated definition of a net class wecallextended
Linear Time Algorithm to Find a Minimal Deadlock in a Strongly Connected FreeChoice Net
, 1993
"... This paper presents an improved algorithm compared to the one given in [7], which finds a minimal deadlock containing a given place p in a strongly connected FreeChoice net (FCnet). Its worst case time complexity is linear in the size of the net. The interest in finding such deadlocks arises f ..."
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Cited by 2 (0 self)
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This paper presents an improved algorithm compared to the one given in [7], which finds a minimal deadlock containing a given place p in a strongly connected FreeChoice net (FCnet). Its worst case time complexity is linear in the size of the net. The interest in finding such deadlocks arises from recognising structurally live and bounded FCnets (LBFCnets), where finding structural deadlocks efficiently is crucial for the algorithm's time complexity. Employing this new algorithm within [7] LBFCnets can be recognised in O(P² T), which is a reduction by one order of magnitude. Furthermore this marks a lower limit for the complexity of algorithms based on the rank theorem as long as the computation of a matrix rank requires O(n³).
On Synchronous and Asynchronous Interaction in Distributed Systems
"... When considering distributed systems, it is a central issue how to deal with interactions between components. In this paper, we investigate the paradigms of synchronous and asynchronous interaction in the context of distributed systems. We investigate to what extent or under which conditions synch ..."
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When considering distributed systems, it is a central issue how to deal with interactions between components. In this paper, we investigate the paradigms of synchronous and asynchronous interaction in the context of distributed systems. We investigate to what extent or under which conditions synchronous interaction is a valid concept for specification and implementation of such systems. We choose Petri nets as our system model and consider different notions of distribution by associating locations to elements of nets. First, we investigate the concept of simultaneity which is inherent in the semantics of Petri nets when transitions have multiple input places. We assume that tokens may only be taken instantaneously by transitions on the same location. We exhibit a hierarchy of ‘asynchronous ’ Petri net classes by different assumptions on possible distributions. Alternatively, we assume that the synchronisations specified in a Petri net are crucial system properties. Hence transitions and their preplaces may no longer placed on separate locations. We then answer the question which systems may be implemented in a distributed way without restricting concurrency, assuming that locations are inherently sequential. It turns out that in both settings we find semistructural properties of Petri nets describing exactly the problematic situations for interactions in distributed systems.
tue.nl (A.J.M.M. Weijters).
, 2007
"... (e.g., the Partner Interface Processes in RosettaNet [30], the abstract BPEL processes in the context of web ..."
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(e.g., the Partner Interface Processes in RosettaNet [30], the abstract BPEL processes in the context of web
Liveness, Fairness, and Recurrence in Petri Nets
"... this paper, we will investigate the reverse direction of this implication. In particular, we will characterize a class of Petri nets for which liveness implies recurrence. Basically, this class is asymmetric choice nets [7, 9] which is often also called extended simple nets [8, 6]. Since we extend t ..."
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this paper, we will investigate the reverse direction of this implication. In particular, we will characterize a class of Petri nets for which liveness implies recurrence. Basically, this class is asymmetric choice nets [7, 9] which is often also called extended simple nets [8, 6]. Since we extend the class email: kindler@informatik.huberlin.de
Process Equivalence in the Context of Genetic Mining
"... Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discover ..."
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Abstract. In various application domains there is a desire to compare process models, e.g., to relate an organizationspecific process model to a reference model, to find a web service matching some desired service description, or to compare some normative process model with a process model discovered using process mining techniques. Although many researchers have worked on different notions of equivalence (e.g., trace equivalence, bisimulation, branching bisimulation, etc.), most of the existing notions are not very useful in this context. First of all, most equivalence notions result in a binary answer (i.e., two processes are equivalent or not). This is not very helpful, because, in reallife applications, one needs to differentiate between slightly different models and completely different models. Second, not all parts of a process model are equally important. There may be parts of the process model that are rarely activated (i.e., “process veins”) while other parts are executed for most process instances (i.e., the “process arteries”). Clearly, differences in some veins of a process are less important than differences in the main artery of a process. To address the problem, this paper proposes a completely new way of comparing process models. Rather than directly comparing two models, the process models are compared with respect to some typical behavior. This way, we are able to avoid the two problems just mentioned. The approach has been implemented and has been used in the context of genetic process mining. Although the results are presented in the context of Petri nets, the approach can be applied to any process modeling language with executable semantics.