Statechartable Petri nets

Petri nets and statecharts can model concurrent systems in a succinct way. While translations from statecharts to Petri nets exist, a well-defined translation from Petri nets to statecharts is lacking. Such a translation should map an input net to a corresponding statechart, having a structure and behaviour similar to that of the input net. Since statecharts can only model a restricted form of concurrency, not every Petri net has a corresponding statechart. We identify a class of Petri nets, called statechartable nets, that can be translated to corresponding statecharts. Statechartable Petri nets are structurally defined using the novel notion of an area. We also define a structural translation that maps each statechartable Petri net to a corresponding statechart. The translation is proven sound and complete for statechartable Petri nets

Extracting Features From Process Variants in Case Management

Case Management supports knowledge workers in performing knowledge-intensive processes in a flexible way. An essential ingredient of Case Management are template processes that are modified for a specific case to suit the context of that case. Modifying templates results in many different yet related process variants. However, modifying a template is time consuming and may lead to errors. This paper defines an approach to extract fragments, called features, from artifact-centric process variants in case management. By composing the extracted features, the input variants and other process variants can be derived. This way, complex artifact-centric process variants can be designed more efficiently and their quality improves, since well-known modifications are applied

Translating safe Petri nets to statecharts in a structure-preserving way

Statecharts and Petri nets are two popular visual formalisms for modelling complex systems that exhibit concurrency. Both formalisms are supported by various design tools. To enable the automated exchange of models between Petri net and statechart tools, we present a structural, polynomial algorithm that translates safe Petri nets into statecharts. The translation algorithm preserves both the structure and the behaviour of the input net. The algorithm can fail, since not every safe net has a statechart translation that preserves both its structure and behaviour. The class of safe nets for which the algorithm succeeds is formally characterised. Some statechart translations are not constructible by the algorithm, but this does not seem to be a severe limitation in practice

An integer programming based approach for verification and diagnosis of workflows

Workflow analysis is indispensable to capture modeling errors in workflow designs. While several workflow analysis approaches have been defined previously, these approaches do not give precise feedback, thus making it hard for a designer to pinpoint the exact cause of modeling errors. In this paper we introduce a novel approach for analyzing and diagnosing workflows based on integer programming (IP). Each workflow model is translated into a set of IP constraints. Faulty control flow connectors can be easily detected using the approach by relaxing the corresponding constraints. We have implemented this diagnosis approach in a tool called DiagFlow which reads and diagnoses XPDL models using an existing open source IP solver as a backend. We show that the diagnosis approach is correct and illustrate it with realistic examples. Moreover, the approach is flexible and can be extended to handle a variety of new constraints, as well as to support new workflow patterns. Results of testing on large process models show that DiagFlow outperforms a state of the art tool like Woflan in terms of the solution time

Assessing suitability of adaptive case management

Business Process Management (BPM) includes methods and techniques to support the execution of business processes. In recent years, Adaptive Case Management (ACM) has been proposed as new BPM technology for supporting knowledge-intensive processes. However, there is currently no structured way of quickly deciding upon the suitability of an ACM system to a specific business process. This paper presents a framework for assessing to which extent ACM is suitable for a particular business process. It distinguishes between process characteristics that ACM can support, characteristics that ACM can support but are not ideal, and characteristics that ACM cannot support. The framework also explains the rationale behind each assessment, and refers to alternatives in case ACM is not suitable for the process that needs to be supported. Thus, the framework provides a transparent and useful advice about which kind of BPM technology is most suitable to support a business process to the best extent. A preliminary evaluation of the framework has been carried out in collaboration with an IT consultancy company that advises its clients on BPM technology

Modeling uncertainty in declarative artifact-centric process models

Many knowledge-intensive processes are driven by business entities about which knowledge workers make decisions and to which they add information. Artifact-centric process models have been proposed to represent such knowledge-intensive processes. Declarative artifact-centric process models use business rules that define how knowledge experts can make progress in a process. However, in many business situations knowledge experts have to deal with uncertainty and vagueness. Currently, how to deal with such situations cannot be expressed in declarative artifact-centric process models. We propose the use of fuzzy logic to model uncertainty. We use Guard-Stage-Milestone schemas as declarative artifact-centric process notation and we extend them with fuzzy sentries. We explain how the resulting fuzzy GSM schemas can be evaluated by extending an existing GSM engine with a tool for fuzzy evaluation of rules. We evaluate fuzzy GSM schemas by applying them to an existing fragment of regulations for handling a mortgage contract

Reasoning about property preservation in adaptive case management

Adaptive Case Management (ACM) has emerged as a key BPM technology for supporting the unstructured business process. A key problem in ACM is that case schemas need to be changed to best fit the case at hand. Such changes are ad hoc, and may result in schemas that do not reflect the intended logic or properties. This article presents a formal approach for reasoning about which properties of a case schema are preserved after a modification, and describes change operations that are guaranteed to preserve certain properties. The approach supports reasoning about rollbacks. The Case Management model used here is a variant of the Guard-Stage-Milestone model for declarative business artifacts. A real-life example illustrates applicability

Flexible construction of executable service compositions from reusable semantic knowledge

Most service composition approaches rely on top-down decomposition of a problem and AI-style planning to assemble service components into a meaningful whole, impeding reuse and flexibility. In this article, we propose an approach that starts from declarative knowledge about the semantics of individual service components and algorithmically constructs a full-blown service orchestration process that supports sequence, choice, and parallelism. The output of our algorithm can be mapped directly into a number of service orchestration languages such as OWL-S and BPEL. The approach consists of two steps. First, semantic links specifying data dependencies among the services are derived and organized in a flexible network. Second, based on a user request indicating the desired outcomes from the composition, an executable composition is constructed from the network that satisfies the dependencies. The approach is unique in producing complex compositions out of semantic links between services in a flexible way. It also allows reusing knowledge about semantic dependencies in the network to generate new compositions through new requests and modification of services at runtime. The approach has been implemented in a prototype that outperforms related composition prototypes in experiments