Reduction rules for YAWL workflow nets with cancellation regions and OR-joins

A reduction rule can transform a large net into a smaller and simple net while preserving certain interesting properties and it is usually applied before verification to reduce the complexity and to prevent state space explosion. Reset nets have been proposed to formally describe workflows with cancellation behaviour. In our previous work, we have presented a set of reduction rules for Reset Workflow Net (RWF-net), which is a subclass of reset nets. In this paper, we will present a set of reduction rules for YAWL nets with cancellation regions and OR-joins. The reduction rules for RWF-nets combined with the formal mappings from YAWL nets provide us with the means to dene a set of reduction rules for YAWL nets. We will also demonstrate how these reduction rules can be used for efficient verification of YAWL nets these features

Reduction rules for reset workflow nets

When a workflow contains a large number of tasks and involves complex control flow dependencies, verification can take too much time or it may even be impossible. Reduction rules can be used to abstract from certain transitions and places in a large net and thus could cut down the size of the net used for verification. Petri nets have been proposed to model and analyse workflows and Petri nets reduction rules have been used for efficient verification of various properties of workflows, such as liveness and boundedness. Reset nets are Petri nets with reset arcs, which can remove tokens from places when a transition fires. The nature of reset arcs closely relates to the cancellation behaviour in workflows. As a result, reset nets have been proposed to formally represent workflows with cancellation behaviour, which is not easily modelled in ordinary Petri nets. Even though reduction rules exist for Petri nets, the nature of reset arcs could invalidate the transformation rules applicable to Petri nets. This motivated us to consider possible reduction rules for reset nets. In this paper, we propose a number of reduction rules for Reset Workflow Nets (RWF-nets) that are soundness preserving. These reduction rules are based on reduction rules available for Petri nets [19] and we present the necessary conditions under which these rules hold in the context of reset nets

Workflow simulation for operational decision support using YAWL and ProM

Simulation is widely used as a tool for analyzing business processes but is mostly focused on examining rather abstract steady-state situations. Such analyses are helpful for the initial design of a business process but are less suitable for operational decision making and continuous improvement. Here we describe a simulation system for operational decision support in the context of work ow management. To do this we exploit not only the work ow's design, but also logged data describing the system's observed historic behavior, and information extracted about the current state of the work ow. Making use of actual data capturing the current state and historic information allows our simulations to accurately predict potential near-future behaviors for dierent scenarios. The approach is supported by a practical toolset which combines and extends the work ow management system YAWL and the process mining framework ProM. This technical report contains a detailed description of how a simulation model including operational decision support can be generated by our software based on the running example

Soundness of workflow nets : classification, decidability, and analysis

Workflow nets, a particular class of Petri nets, have become one of the standard ways to model and analyze workflows. Typically, they are used as an abstraction of the workflow that is used to check the so-called soundness property. This property guarantees the absence of livelocks, deadlocks, and other anomalies that can be detected without domain knowledge. Several authors have proposed alternative notions of soundness and have suggested to use more expressive languages, e.g., models with cancellations or priorities. This paper provides an overview of the different notions of soundness and investigates these in the presence of different extensions of workflow nets. We will show that the eight soundness notions described in the literature are decidable for workflow nets. However, most extensions will make all of these notions undecidable. These new results show the theoretical limits of workflow verification. Moreover, we discuss some of the analysis approaches described in the literature

Abstracting modelling languages: A reutilization approach

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-31095-9_9Proceedings of 24th International Conference, CAiSE 2012, Gdansk, Poland, June 25-29, 2012Model-Driven Engineering automates the development of information systems. This approach is based on the use of Domain-Specific Modelling Languages (DSMLs) for the description of the relevant aspects of the systems to be built. The increasing complexity of the target systems has raised the need for abstraction techniques able to produce simpler versions of the models, but retaining certain properties of interest. However, developing such abstractions for each DSML from scratch is a time and resource consuming activity. Our solution to this situation is a number of techniques to build reusable abstractions that are defined once and can be reused over families of modelling languages sharing certain requirements. As a proof of concept, we present a catalogue of reusable abstractions, together with an implementation in the MetaDepth multi-level meta-modelling tool.Work funded by the Spanish Ministry of Economy and Competitivity (TIN2011-24139), and the R&D programme of Madrid Region (S2009/TIC-1650)

Understanding process behaviours in a large insurance company in Australia: A case study

Having a reliable understanding about the behaviours, problems, and performance of existing processes is important in enabling a targeted process improvement initiative. Recently, there has been an increase in the application of innovative process mining techniques to facilitate evidence-based understanding about organizations' business processes. Nevertheless, the application of these techniques in the domain of finance in Australia is, at best, scarce. This paper details a 6-month case study on the application of process mining in one of the largest insurance companies in Australia. In particular, the challenges encountered, the lessons learned, and the results obtained from this case study are detailed. Through this case study, we not only validated existing `lessons learned' from other similar case studies, but also added new insights that can be beneficial to other practitioners in applying process mining in their respective fields

Business process simulation for operational decision support

Contemporary business process simulation environments are geared towards design-time analysis, rather than operational decision support over already deployed and running processes. In particular, simulation experiments in existing process simulation environments start from an empty execution state. We investigate the requirements for a process simulation environment that allows simulation experiments to start from an intermediate execution state. We propose an architecture addressing these requirements and demonstrate it through a case study conducted using the YAWL workflow engine and CPN simulation tools

Semantics of Standard Process Models with OR-joins

The Business Process Modeling Notation (BPMN) is an emerging standard for capturing business processes. Like its predecessors, BPMN lacks a formal semantics and many of its features are subject to interpretation. One construct of BPMN that has an ambiguous semantics is the OR-join. Several formal semantics of this construct have been proposed for similar languages such as EPCs and YAWL. However, these existing semantics are computationally expensive. This paper formulates a semantics of the OR-join in BPMN for which enablement of a given OR-join in a model can be evaluated in quadratic time in terms of the total number of elements in the model. This complexity can be reduced to linear-time after materializing a quadratic-sized data structure at design-time. The paper also shows how to evaluate enablement of an OR-join incrementally as the execution of a process instance unfolds

On the Suitability of BPMN for Business Process Modelling

In this paper we examine the suitability of the Business Process Modelling Notation (BPMN) for business process modelling, using the Workflow Patterns as an evaluation framework. The Workflow Patterns are a collection of patterns developed for assessing control-flow, data and resource capabilities in the area of Process Aware Information Systems (PAISs). In doing so, we provide a comprehensive evaluation of the capabilities of BPMN, and its strengths and weaknesses when utilised for business process modelling. The analysis provided for BPMN is part of a larger effort aiming at an unbiased and vendor-independent survey of the suitability and the expressive power of some mainstream process modelling languages. It is a sequel to previous work in which languages including BPEL and UML Activity Diagrams were evaluated