Abstract. The topic of process mining has attracted the attention of both researchers and tool vendors in the Business Process Management (BPM) space. The goal of process mining is to discover process models from event logs, i.e., events logged by some information system are used to extract information about activities and their causal relations. Several algorithms have been proposed for process mining. Many of these algorithms cannot deal with concurrency. Other typical problems are the presence of duplicate activities, hidden activities, non-free-choice constructs, etc. In addition, real-life logs contain noise (e.g., exceptions or incorrectly logged events) and are typically incomplete (i.e., the event logs contain only a fragment of all possible behaviors). To tackle these problems we propose a completely new approach based on genetic algorithms. As can be expected, a genetic approach is able to deal with noise and incompleteness. However, it is not easy to represent processes properly in a genetic setting. In this paper, we show a genetic process mining approach using the so-called causal matrix as a representation for individuals. We elaborate on the relation between Petri nets and this representation and show that genetic algorithms can be used to discover Petri net models from event logs.

Abstract. Business process models, often modelled using graphical languages like UML, serve asabase for communication between the stakeholders inthe software development process. To fulfill this purpose, they should be easy to understand and easy to maintain. Forthis reason, itisuseful tohave measures that can give ussome information aboutunderstandabilityand maintainabilityofabusiness process model. Such measures should tell uswhether the model has an appropriate size, is clearly structured, easy to comprehend and partitioned into modules in asensible way. This paper discusses how existing research results onthe complexity of software can be extended inorder toanalyze the complexity ofbusiness process models. 1

Abstract. This paper describes use of the formal modeling language Colored Petri Nets (CPNs) in the development of a new bank system. As a basis for the paper, we present a requirements model, intheformof a CPN, which describes a new bank work process that must be supported by the new system. This model has been used to specify, validate, and elicit user requirements. The contribution of this paper is to describe two translation steps that go from the requirements CPN to an implementation of the new system. In the first translation step, a workflow model is derived from the requirements model. This model is represented in terms of a so-called Colored Workflow Net (CWN), which is a generalization of the classical workflow nets to CPN. In the second translation step, the CWN is translated into implementation code. The target implementation language is BPEL4WS deployed in the context of IBM WebSphere. A semi-automatic translation of the workflow model to BPEL4WS is possible because of the structural requirements imposed on CWNs.

Abstract. Designing business models is a complicated and error prone task. On the one hand, business models need to be intuitive and easy to understand. On the other hand, ambiguities may lead to different interpretations and false consensus. Moreover, to configure process-aware information systems (e.g., a workflow system), the business model needs to be transformed into an executable model. Event-driven Process Chains (EPCs), but also other informal languages, are intended as a language to support the transition from a business model to an executable model. Many researchers have assigned formal semantics to EPCs and are using these semantics for execution and verification. In this paper, we use a different tactic. We propose a two-step approach where first the informal model is reduced and then verified in an interactive manner. This approach acknowledges that some constructs are correct or incorrect no matter what interpretation is used and that the remaining constructs require human judgment to assess correctness. This paper presents a software tool that supports this two-step approach and thus allows for the verification of real-life EPCs as illustrated by two case studies. 1

Up to now there is neither data available on how many errors can be expected in process model collections, nor is it understood why errors are introduced. In this article, we provide empirical evidence for these questions based on the SAP reference model. This model collection contains about 600 process models expressed as Eventdriven Process Chains (EPCs). We translated these EPCs into YAWL models, and analyzed them using the verification tool WofYAWL. We discovered that at least 34 of these EPCs contain errors. Moreover, we used logistic regression to show that

The correctness of business process models is of paramount importance for the application on an enterprise level. A severe problem is that several languages for business process modelling do not have formal execution semantics which is a prerequisite to check correctness criteria. In this context, soundness defines a minimum correctness criterion that a process model should fulfil. In this paper we present a novel approach to reason about soundness based on so-called causal footprints. A causal footprint represents a set of conditions on the order of activities that holds for every case of a process model. We identify three kinds of error patterns that affect the soundness of a process model, namely the deadlock pattern, the multiple termination pattern, and the trap pattern. We use Eventdriven Process Chains (EPCs) and Petri nets to demonstrate the applicability of our approach for both conceptual as for formal process modelling languages. Furthermore, it can easily be applied to other languages, such as UML activity diagrams or BPEL. Based on the trap pattern, we prove that the “vicious circle”, that is heavily discussed in EPC literature, is unsound. 1.

YAWL (Yet Another Workflow Language) workflow language supports the most frequent control-flow patterns found in the current workflow practice. As a result, most workflow languages can be mapped onto YAWL without the loss of control-flow details, even languages allowing for advanced constructs such as cancellation regions and OR-joins. Hence, a verification approach for YAWL is desirable, because such an approach could be used for any workflow language that can be mapped onto YAWL. Unfortunately, cancellation regions and OR-joins are ‘non-local ’ properties, and in general we cannot even decide whether the desired final state is reachable if both patterns are present. This paper proposes a verification approach based on (i) an abstraction of the OR-join semantics; (ii) the relaxed soundness property; and (iii) transition invariants. This approach is correct (errors reported are really errors), but not necessarily complete (not every error might get reported). This incompleteness can be explained because, on the one hand, the approach abstracts from the OR-join semantics and on the other hand, it may use only transition invariants, which are structural properties. Nevertheless, our approach can be used to successfully detect errors in YAWL models. Moreover, the approach can be easily transferred to other workflow languages allowing for advanced constructs such as cancellations and OR-joins.

Controllability is a fundamental correctness criterion for interacting service models. A service model is controllable if there exists a partner service such that their composition is free of deadlocks and livelocks. Whereas controllability can be automatically decided, the existing decision algorithm gives no information about the reasons of why a service model is uncontrollable. This paper introduces a diagnosis framework to find these reasons which can help to fix uncontrollable service models.

Abstract. Although several process modeling languages allow one to specify processes with multiple start elements, the precise semantics of such models are often unclear, both from a pragmatic and from a theoretical point of view. This paper addresses the lack of research on this problem and introduces the CASU framework. The contribution of this framework is a systematic description of design alternatives for the specification of instantiation semantics of process modeling languages. We classify six of the most prominent languages by the help of this framework. Our work provides the basis for the design of new correctness criteria as well as for the formalization of EPCs and extension of BPMN. It complements research such as the workflow patterns. 1

We study the correct interaction between services using the following notion for correctness: there is no deadlock in the interaction of the services, and a given set of activities is not dead, that is, each activity in this set is executed in at least one run. The second condition has not been studied before. An operating guideline of a service P is an operational characterization of all deadlock-free interacting partners of P. In this paper, we present an extension of the concept of an operating guideline to characterize all correctly interacting partners of a service P. This extension can be used for answering at least the following two questions. First, given a service R, does R interact correctly with P? Second, given a service P ′ , can P be substituted by P ′ , that is, is every correctly interacting partner of P a correctly interacting partner of P ′ , too? Key words: Business process modeling and analysis, Process verification and validation, operating guidelines, substitutability,